Make Spack core PEP8 compliant.

147 files changed, 1415 insertions, 1153 deletions

diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py
index 4cf99163e0..22ca85abf9 100644
--- a/lib/spack/llnl/util/filesystem.py
+++ b/lib/spack/llnl/util/filesystem.py
@@ -106,6 +106,7 @@ def filter_file(regex, repl, *filenames, **kwargs):
 
 class FileFilter(object):
     """Convenience class for calling filter_file a lot."""
+
     def __init__(self, *filenames):
         self.filenames = filenames
 
@@ -355,7 +356,8 @@ def traverse_tree(source_root, dest_root, rel_path='', **kwargs):
             # When follow_nonexisting isn't set, don't descend into dirs
             # in source that do not exist in dest
             if follow_nonexisting or os.path.exists(dest_child):
-                tuples = traverse_tree(source_root, dest_root, rel_child, **kwargs)  # NOQA: ignore=E501
+                tuples = traverse_tree(
+                    source_root, dest_root, rel_child, **kwargs)
                 for t in tuples:
                     yield t
 
@@ -422,14 +424,20 @@ def fix_darwin_install_name(path):
     libs = glob.glob(join_path(path, "*.dylib"))
     for lib in libs:
         # fix install name first:
-        subprocess.Popen(["install_name_tool", "-id", lib, lib], stdout=subprocess.PIPE).communicate()[0]  # NOQA: ignore=E501
-        long_deps = subprocess.Popen(["otool", "-L", lib], stdout=subprocess.PIPE).communicate()[0].split('\n')  # NOQA: ignore=E501
+        subprocess.Popen(
+            ["install_name_tool", "-id", lib, lib],
+            stdout=subprocess.PIPE).communicate()[0]
+        long_deps = subprocess.Popen(
+            ["otool", "-L", lib],
+            stdout=subprocess.PIPE).communicate()[0].split('\n')
         deps = [dep.partition(' ')[0][1::] for dep in long_deps[2:-1]]
         # fix all dependencies:
         for dep in deps:
             for loc in libs:
                 if dep == os.path.basename(loc):
-                    subprocess.Popen(["install_name_tool", "-change", dep, loc, lib], stdout=subprocess.PIPE).communicate()[0]  # NOQA: ignore=E501
+                    subprocess.Popen(
+                        ["install_name_tool", "-change", dep, loc, lib],
+                        stdout=subprocess.PIPE).communicate()[0]
                     break
 
 
diff --git a/lib/spack/llnl/util/lang.py b/lib/spack/llnl/util/lang.py
index 63eb08d803..df32012e2d 100644
--- a/lib/spack/llnl/util/lang.py
+++ b/lib/spack/llnl/util/lang.py
@@ -24,7 +24,6 @@
 ##############################################################################
 import os
 import re
-import sys
 import functools
 import collections
 import inspect
@@ -39,14 +38,15 @@ def index_by(objects, *funcs):
        Values are used as keys.  For example, suppose you have four
        objects with attributes that look like this:
 
-           a = Spec(name="boost",    compiler="gcc",   arch="bgqos_0")
-           b = Spec(name="mrnet",    compiler="intel", arch="chaos_5_x86_64_ib")
-           c = Spec(name="libelf",   compiler="xlc",   arch="bgqos_0")
-           d = Spec(name="libdwarf", compiler="intel", arch="chaos_5_x86_64_ib")
+          a = Spec(name="boost",    compiler="gcc",   arch="bgqos_0")
+          b = Spec(name="mrnet",    compiler="intel", arch="chaos_5_x86_64_ib")
+          c = Spec(name="libelf",   compiler="xlc",   arch="bgqos_0")
+          d = Spec(name="libdwarf", compiler="intel", arch="chaos_5_x86_64_ib")
 
-           list_of_specs = [a,b,c,d]
-           index1 = index_by(list_of_specs, lambda s: s.arch, lambda s: s.compiler)
-           index2 = index_by(list_of_specs, lambda s: s.compiler)
+          list_of_specs = [a,b,c,d]
+          index1 = index_by(list_of_specs, lambda s: s.arch,
+                            lambda s: s.compiler)
+          index2 = index_by(list_of_specs, lambda s: s.compiler)
 
        ``index1'' now has two levels of dicts, with lists at the
        leaves, like this:
@@ -137,7 +137,7 @@ def get_calling_module_name():
     finally:
         del stack
 
-    if not '__module__' in caller_locals:
+    if '__module__' not in caller_locals:
         raise RuntimeError("Must invoke get_calling_module_name() "
                            "from inside a class definition!")
 
@@ -173,11 +173,11 @@ def has_method(cls, name):
 class memoized(object):
     """Decorator that caches the results of a function, storing them
        in an attribute of that function."""
+
     def __init__(self, func):
         self.func = func
         self.cache = {}
 
-
     def __call__(self, *args):
         if not isinstance(args, collections.Hashable):
             # Not hashable, so just call the function.
@@ -187,12 +187,10 @@ class memoized(object):
             self.cache[args] = self.func(*args)
         return self.cache[args]
 
-
     def __get__(self, obj, objtype):
         """Support instance methods."""
         return functools.partial(self.__call__, obj)
 
-
     def clear(self):
         """Expunge cache so that self.func will be called again."""
         self.cache.clear()
@@ -237,13 +235,21 @@ def key_ordering(cls):
     if not has_method(cls, '_cmp_key'):
         raise TypeError("'%s' doesn't define _cmp_key()." % cls.__name__)
 
-    setter('__eq__', lambda s,o: (s is o) or (o is not None and s._cmp_key() == o._cmp_key()))
-    setter('__lt__', lambda s,o: o is not None and s._cmp_key() <  o._cmp_key())
-    setter('__le__', lambda s,o: o is not None and s._cmp_key() <= o._cmp_key())
-
-    setter('__ne__', lambda s,o: (s is not o) and (o is None or s._cmp_key() != o._cmp_key()))
-    setter('__gt__', lambda s,o: o is None or s._cmp_key() >  o._cmp_key())
-    setter('__ge__', lambda s,o: o is None or s._cmp_key() >= o._cmp_key())
+    setter('__eq__',
+           lambda s, o:
+           (s is o) or (o is not None and s._cmp_key() == o._cmp_key()))
+    setter('__lt__',
+           lambda s, o: o is not None and s._cmp_key() < o._cmp_key())
+    setter('__le__',
+           lambda s, o: o is not None and s._cmp_key() <= o._cmp_key())
+
+    setter('__ne__',
+           lambda s, o:
+           (s is not o) and (o is None or s._cmp_key() != o._cmp_key()))
+    setter('__gt__',
+           lambda s, o: o is None or s._cmp_key() > o._cmp_key())
+    setter('__ge__',
+           lambda s, o: o is None or s._cmp_key() >= o._cmp_key())
 
     setter('__hash__', lambda self: hash(self._cmp_key()))
 
@@ -254,10 +260,10 @@ def key_ordering(cls):
 class HashableMap(dict):
     """This is a hashable, comparable dictionary.  Hash is performed on
        a tuple of the values in the dictionary."""
+
     def _cmp_key(self):
         return tuple(sorted(self.values()))
 
-
     def copy(self):
         """Type-agnostic clone method.  Preserves subclass type."""
         # Construct a new dict of my type
@@ -336,24 +342,39 @@ def match_predicate(*args):
     return match
 
 
-
 def DictWrapper(dictionary):
     """Returns a class that wraps a dictionary and enables it to be used
        like an object."""
     class wrapper(object):
-        def __getattr__(self, name):        return dictionary[name]
-        def __setattr__(self, name, value): dictionary[name] = value
-        def setdefault(self, *args):        return dictionary.setdefault(*args)
-        def get(self, *args):               return dictionary.get(*args)
-        def keys(self):                     return dictionary.keys()
-        def values(self):                   return dictionary.values()
-        def items(self):                    return dictionary.items()
-        def __iter__(self):                 return iter(dictionary)
 
+        def __getattr__(self, name):
+            return dictionary[name]
+
+        def __setattr__(self, name, value):
+            dictionary[name] = value
+
+        def setdefault(self, *args):
+            return dictionary.setdefault(*args)
+
+        def get(self, *args):
+            return dictionary.get(*args)
+
+        def keys(self):
+            return dictionary.keys()
+
+        def values(self):
+            return dictionary.values()
+
+        def items(self):
+            return dictionary.items()
+
+        def __iter__(self):
+            return iter(dictionary)
 
     return wrapper()
 
 
 class RequiredAttributeError(ValueError):
+
     def __init__(self, message):
         super(RequiredAttributeError, self).__init__(message)
diff --git a/lib/spack/llnl/util/link_tree.py b/lib/spack/llnl/util/link_tree.py
index b6d8796084..d6547e933a 100644
--- a/lib/spack/llnl/util/link_tree.py
+++ b/lib/spack/llnl/util/link_tree.py
@@ -23,12 +23,13 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 """LinkTree class for setting up trees of symbolic links."""
-__all__ = ['LinkTree']
 
 import os
 import shutil
 from llnl.util.filesystem import *
 
+__all__ = ['LinkTree']
+
 empty_file_name = '.spack-empty'
 
 
@@ -43,13 +44,13 @@ class LinkTree(object):
     modified.
 
     """
+
     def __init__(self, source_root):
         if not os.path.exists(source_root):
             raise IOError("No such file or directory: '%s'", source_root)
 
         self._root = source_root
 
-
     def find_conflict(self, dest_root, **kwargs):
         """Returns the first file in dest that conflicts with src"""
         kwargs['follow_nonexisting'] = False
@@ -61,9 +62,9 @@ class LinkTree(object):
                 return dest
         return None
 
-
     def merge(self, dest_root, **kwargs):
-        """Link all files in src into dest, creating directories if necessary."""
+        """Link all files in src into dest, creating directories
+           if necessary."""
         kwargs['order'] = 'pre'
         for src, dest in traverse_tree(self._root, dest_root, **kwargs):
             if os.path.isdir(src):
@@ -83,7 +84,6 @@ class LinkTree(object):
                 assert(not os.path.exists(dest))
                 os.symlink(src, dest)
 
-
     def unmerge(self, dest_root, **kwargs):
         """Unlink all files in dest that exist in src.
 
diff --git a/lib/spack/llnl/util/lock.py b/lib/spack/llnl/util/lock.py
index 4a4aec2385..aa8272d5fe 100644
--- a/lib/spack/llnl/util/lock.py
+++ b/lib/spack/llnl/util/lock.py
@@ -47,6 +47,7 @@ class Lock(object):
     and recent NFS versions.
 
     """
+
     def __init__(self, file_path):
         self._file_path = file_path
         self._fd = None
@@ -225,6 +226,7 @@ class LockTransaction(object):
 
 
 class ReadTransaction(LockTransaction):
+
     def _enter(self):
         return self._lock.acquire_read(self._timeout)
 
@@ -233,6 +235,7 @@ class ReadTransaction(LockTransaction):
 
 
 class WriteTransaction(LockTransaction):
+
     def _enter(self):
         return self._lock.acquire_write(self._timeout)
 
diff --git a/lib/spack/llnl/util/tty/__init__.py b/lib/spack/llnl/util/tty/__init__.py
index ee81e11a20..db74aaba6b 100644
--- a/lib/spack/llnl/util/tty/__init__.py
+++ b/lib/spack/llnl/util/tty/__init__.py
@@ -36,6 +36,7 @@ _debug   = False
 _verbose = False
 indent  = "  "
 
+
 def is_verbose():
     return _verbose
 
@@ -148,7 +149,8 @@ def get_yes_or_no(prompt, **kwargs):
     elif default_value is False:
         prompt += ' [y/N] '
     else:
-        raise ValueError("default for get_yes_no() must be True, False, or None.")
+        raise ValueError(
+            "default for get_yes_no() must be True, False, or None.")
 
     result = None
     while result is None:
@@ -174,8 +176,9 @@ def hline(label=None, **kwargs):
     char      = kwargs.pop('char', '-')
     max_width = kwargs.pop('max_width', 64)
     if kwargs:
-        raise TypeError("'%s' is an invalid keyword argument for this function."
-                        % next(kwargs.iterkeys()))
+        raise TypeError(
+            "'%s' is an invalid keyword argument for this function."
+            % next(kwargs.iterkeys()))
 
     rows, cols = terminal_size()
     if not cols:
@@ -200,7 +203,8 @@ def terminal_size():
     """Gets the dimensions of the console: (rows, cols)."""
     def ioctl_GWINSZ(fd):
         try:
-            rc = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
+            rc = struct.unpack('hh', fcntl.ioctl(
+                fd, termios.TIOCGWINSZ, '1234'))
         except:
             return
         return rc
diff --git a/lib/spack/llnl/util/tty/colify.py b/lib/spack/llnl/util/tty/colify.py
index 81a83691d7..67acdfa517 100644
--- a/lib/spack/llnl/util/tty/colify.py
+++ b/lib/spack/llnl/util/tty/colify.py
@@ -27,15 +27,14 @@ Routines for printing columnar output.  See colify() for more information.
 """
 import os
 import sys
-import fcntl
-import termios
-import struct
 from StringIO import StringIO
 
 from llnl.util.tty import terminal_size
 from llnl.util.tty.color import clen, cextra
 
+
 class ColumnConfig:
+
     def __init__(self, cols):
         self.cols = cols
         self.line_length = 0
@@ -43,7 +42,8 @@ class ColumnConfig:
         self.widths = [0] * cols   # does not include ansi colors
 
     def __repr__(self):
-        attrs = [(a,getattr(self, a)) for a in dir(self) if not a.startswith("__")]
+        attrs = [(a, getattr(self, a))
+                 for a in dir(self) if not a.startswith("__")]
         return "<Config: %s>" % ", ".join("%s: %r" % a for a in attrs)
 
 
@@ -68,7 +68,7 @@ def config_variable_cols(elts, console_width, padding, cols=0):
     max_cols = min(len(elts), max_cols)
 
     # Range of column counts to try.  If forced, use the supplied value.
-    col_range = [cols] if cols else xrange(1, max_cols+1)
+    col_range = [cols] if cols else xrange(1, max_cols + 1)
 
     # Determine the most columns possible for the console width.
     configs = [ColumnConfig(c) for c in col_range]
@@ -106,7 +106,6 @@ def config_uniform_cols(elts, console_width, padding, cols=0):
 
     # 'clen' ignores length of ansi color sequences.
     max_len = max(clen(e) for e in elts) + padding
-    max_clen = max(len(e) for e in elts) + padding
     if cols == 0:
         cols = max(1, console_width / max_len)
         cols = min(len(elts), cols)
@@ -130,17 +129,19 @@ def colify(elts, **options):
     output=<stream>   A file object to write to.  Default is sys.stdout.
     indent=<int>      Optionally indent all columns by some number of spaces.
     padding=<int>     Spaces between columns.  Default is 2.
-    width=<int>       Width of the output.  Default is 80 if tty is not detected.
+    width=<int>       Width of the output.  Default is 80 if tty not detected.
 
     cols=<int>        Force number of columns. Default is to size to terminal,
                       or single-column if no tty
 
     tty=<bool>        Whether to attempt to write to a tty.  Default is to
-                      autodetect a tty. Set to False to force single-column output.
+                      autodetect a tty. Set to False to force
+                      single-column output.
 
-    method=<string>   Method to use to fit columns.  Options are variable or uniform.
-                      Variable-width columns are tighter, uniform columns are all the
-                      same width and fit less data on the screen.
+    method=<string>   Method to use to fit columns.  Options are variable or
+                      uniform. Variable-width columns are tighter, uniform
+                      columns are all the same width and fit less data on
+                      the screen.
     """
     # Get keyword arguments or set defaults
     cols         = options.pop("cols", 0)
@@ -152,8 +153,9 @@ def colify(elts, **options):
     console_cols = options.pop("width", None)
 
     if options:
-        raise TypeError("'%s' is an invalid keyword argument for this function."
-                        % next(options.iterkeys()))
+        raise TypeError(
+            "'%s' is an invalid keyword argument for this function."
+            % next(options.iterkeys()))
 
     # elts needs to be an array of strings so we can count the elements
     elts = [str(elt) for elt in elts]
@@ -167,7 +169,8 @@ def colify(elts, **options):
             r, c = env_size.split('x')
             console_rows, console_cols = int(r), int(c)
             tty = True
-        except: pass
+        except:
+            pass
 
     # Use only one column if not a tty.
     if not tty:
@@ -228,6 +231,7 @@ def colify_table(table, **options):
         raise ValueError("Table is empty in colify_table!")
 
     columns = len(table[0])
+
     def transpose():
         for i in xrange(columns):
             for row in table:
diff --git a/lib/spack/llnl/util/tty/color.py b/lib/spack/llnl/util/tty/color.py
index 0abcb09b97..b0c00f1502 100644
--- a/lib/spack/llnl/util/tty/color.py
+++ b/lib/spack/llnl/util/tty/color.py
@@ -75,25 +75,27 @@ To output an @, use '@@'.  To output a } inside braces, use '}}'.
 import re
 import sys
 
+
 class ColorParseError(Exception):
     """Raised when a color format fails to parse."""
+
     def __init__(self, message):
         super(ColorParseError, self).__init__(message)
 
 # Text styles for ansi codes
-styles = {'*'  : '1',       # bold
-          '_'  : '4',       # underline
-          None : '0' }      # plain
+styles = {'*': '1',       # bold
+          '_': '4',       # underline
+          None: '0'}      # plain
 
 # Dim and bright ansi colors
-colors = {'k' : 30, 'K' : 90,  # black
-          'r' : 31, 'R' : 91,  # red
-          'g' : 32, 'G' : 92,  # green
-          'y' : 33, 'Y' : 93,  # yellow
-          'b' : 34, 'B' : 94,  # blue
-          'm' : 35, 'M' : 95,  # magenta
-          'c' : 36, 'C' : 96,  # cyan
-          'w' : 37, 'W' : 97 } # white
+colors = {'k': 30, 'K': 90,  # black
+          'r': 31, 'R': 91,  # red
+          'g': 32, 'G': 92,  # green
+          'y': 33, 'Y': 93,  # yellow
+          'b': 34, 'B': 94,  # blue
+          'm': 35, 'M': 95,  # magenta
+          'c': 36, 'C': 96,  # cyan
+          'w': 37, 'W': 97}  # white
 
 # Regex to be used for color formatting
 color_re = r'@(?:@|\.|([*_])?([a-zA-Z])?(?:{((?:[^}]|}})*)})?)'
@@ -104,6 +106,7 @@ _force_color = False
 
 
 class match_to_ansi(object):
+
     def __init__(self, color=True):
         self.color = color
 
@@ -179,12 +182,14 @@ def cprint(string, stream=sys.stdout, color=None):
     """Same as cwrite, but writes a trailing newline to the stream."""
     cwrite(string + "\n", stream, color)
 
+
 def cescape(string):
     """Replace all @ with @@ in the string provided."""
     return str(string).replace('@', '@@')
 
 
 class ColorStream(object):
+
     def __init__(self, stream, color=None):
         self._stream = stream
         self._color = color
@@ -196,7 +201,7 @@ class ColorStream(object):
         color = self._color
         if self._color is None:
             if raw:
-                color=True
+                color = True
             else:
                 color = self._stream.isatty() or _force_color
         raw_write(colorize(string, color=color))
diff --git a/lib/spack/llnl/util/tty/log.py b/lib/spack/llnl/util/tty/log.py
index ca82da7b17..b67edcf9cc 100644
--- a/lib/spack/llnl/util/tty/log.py
+++ b/lib/spack/llnl/util/tty/log.py
@@ -36,6 +36,7 @@ import llnl.util.tty.color as color
 # Use this to strip escape sequences
 _escape = re.compile(r'\x1b[^m]*m|\x1b\[?1034h')
 
+
 def _strip(line):
     """Strip color and control characters from a line."""
     return _escape.sub('', line)
@@ -58,10 +59,10 @@ class keyboard_input(object):
     When the with block completes, this will restore settings before
     canonical and echo were disabled.
     """
+
     def __init__(self, stream):
         self.stream = stream
 
-
     def __enter__(self):
         self.old_cfg = None
 
@@ -86,10 +87,9 @@ class keyboard_input(object):
             # Apply new settings for terminal
             termios.tcsetattr(fd, termios.TCSADRAIN, self.new_cfg)
 
-        except Exception, e:
+        except Exception:
             pass  # Some OS's do not support termios, so ignore.
 
-
     def __exit__(self, exc_type, exception, traceback):
         # If termios was avaialble, restore old settings after the
         # with block
@@ -114,6 +114,7 @@ class log_output(object):
     Closes the provided stream when done with the block.
     If echo is True, also prints the output to stdout.
     """
+
     def __init__(self, stream, echo=False, force_color=False, debug=False):
         self.stream = stream
 
@@ -122,7 +123,7 @@ class log_output(object):
         self.force_color = force_color
         self.debug = debug
 
-        # Default is to try file-descriptor reassignment unless the system 
+        # Default is to try file-descriptor reassignment unless the system
         # out/err streams do not have an associated file descriptor
         self.directAssignment = False
 
@@ -130,7 +131,6 @@ class log_output(object):
         """Jumps to __exit__ on the child process."""
         raise _SkipWithBlock()
 
-
     def __enter__(self):
         """Redirect output from the with block to a file.
 
@@ -154,7 +154,8 @@ class log_output(object):
             with self.stream as log_file:
                 with keyboard_input(sys.stdin):
                     while True:
-                        rlist, w, x = select.select([read_file, sys.stdin], [], [])
+                        rlist, w, x = select.select(
+                            [read_file, sys.stdin], [], [])
                         if not rlist:
                             break
 
@@ -211,7 +212,6 @@ class log_output(object):
             if self.debug:
                 tty._debug = True
 
-
     def __exit__(self, exc_type, exception, traceback):
         """Exits on child, handles skipping the with block on parent."""
         # Child should just exit here.
@@ -235,7 +235,7 @@ class log_output(object):
                     sys.stderr = self._stderr
                 else:
                     os.dup2(self._stdout, sys.stdout.fileno())
-                    os.dup2(self._stderr, sys.stderr.fileno())                    
+                    os.dup2(self._stderr, sys.stderr.fileno())
 
                 return False
 
diff --git a/lib/spack/spack/abi.py b/lib/spack/spack/abi.py
index 38cff62af4..064abb9782 100644
--- a/lib/spack/spack/abi.py
+++ b/lib/spack/spack/abi.py
@@ -30,15 +30,15 @@ from spack.spec import CompilerSpec
 from spack.util.executable import Executable, ProcessError
 from llnl.util.lang import memoized
 
+
 class ABI(object):
     """This class provides methods to test ABI compatibility between specs.
        The current implementation is rather rough and could be improved."""
 
     def architecture_compatible(self, parent, child):
-        """Returns true iff the parent and child specs have ABI compatible targets."""
-        return not parent.architecture or not child.architecture \
-                        or parent.architecture == child.architecture
-
+        """Return true if parent and child have ABI compatible targets."""
+        return not parent.architecture or not child.architecture or \
+            parent.architecture == child.architecture
 
     @memoized
     def _gcc_get_libstdcxx_version(self, version):
@@ -61,8 +61,9 @@ class ABI(object):
         else:
             return None
         try:
-            output = rungcc("--print-file-name=%s" % libname, return_output=True)
-        except ProcessError, e:
+            output = rungcc("--print-file-name=%s" % libname,
+                            return_output=True)
+        except ProcessError:
             return None
         if not output:
             return None
@@ -71,7 +72,6 @@ class ABI(object):
             return None
         return os.path.basename(libpath)
 
-
     @memoized
     def _gcc_compiler_compare(self, pversion, cversion):
         """Returns true iff the gcc version pversion and cversion
@@ -82,7 +82,6 @@ class ABI(object):
             return False
         return plib == clib
 
-
     def _intel_compiler_compare(self, pversion, cversion):
         """Returns true iff the intel version pversion and cversion
            are ABI compatible"""
@@ -92,9 +91,8 @@ class ABI(object):
             return False
         return pversion.version[:2] == cversion.version[:2]
 
-
     def compiler_compatible(self, parent, child, **kwargs):
-        """Returns true iff the compilers for parent and child specs are ABI compatible"""
+        """Return true if compilers for parent and child are ABI compatible."""
         if not parent.compiler or not child.compiler:
             return True
 
@@ -109,8 +107,8 @@ class ABI(object):
         # TODO: into compiler classes?
         for pversion in parent.compiler.versions:
             for cversion in child.compiler.versions:
-                # For a few compilers use specialized comparisons.  Otherwise
-                # match on version match.
+                # For a few compilers use specialized comparisons.
+                # Otherwise match on version match.
                 if pversion.satisfies(cversion):
                     return True
                 elif (parent.compiler.name == "gcc" and
@@ -121,9 +119,8 @@ class ABI(object):
                     return True
         return False
 
-
     def compatible(self, parent, child, **kwargs):
         """Returns true iff a parent and child spec are ABI compatible"""
         loosematch = kwargs.get('loose', False)
         return self.architecture_compatible(parent, child) and \
-               self.compiler_compatible(parent, child, loose=loosematch)
+            self.compiler_compatible(parent, child, loose=loosematch)
diff --git a/lib/spack/spack/architecture.py b/lib/spack/spack/architecture.py
index 886e170b1a..0d210f9741 100644
--- a/lib/spack/spack/architecture.py
+++ b/lib/spack/spack/architecture.py
@@ -91,6 +91,7 @@ import spack.error as serr
 
 
 class NoPlatformError(serr.SpackError):
+
     def __init__(self):
         super(NoPlatformError, self).__init__(
             "Could not determine a platform for this machine.")
diff --git a/lib/spack/spack/cmd/__init__.py b/lib/spack/spack/cmd/__init__.py
index 230115df50..f69f434afd 100644
--- a/lib/spack/spack/cmd/__init__.py
+++ b/lib/spack/spack/cmd/__init__.py
@@ -240,4 +240,4 @@ def display_specs(specs, **kwargs):
         else:
             raise ValueError(
                 "Invalid mode for display_specs: %s. Must be one of (paths,"
-                "deps, short)." % mode)  # NOQA: ignore=E501
+                "deps, short)." % mode)
diff --git a/lib/spack/spack/cmd/activate.py b/lib/spack/spack/cmd/activate.py
index 9867fa8835..797cdcb136 100644
--- a/lib/spack/spack/cmd/activate.py
+++ b/lib/spack/spack/cmd/activate.py
@@ -29,12 +29,14 @@ import spack.cmd
 
 description = "Activate a package extension."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-f', '--force', action='store_true',
         help="Activate without first activating dependencies.")
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="spec of package extension to activate.")
+        'spec', nargs=argparse.REMAINDER,
+        help="spec of package extension to activate.")
 
 
 def activate(parser, args):
diff --git a/lib/spack/spack/cmd/arch.py b/lib/spack/spack/cmd/arch.py
index cf2f96fd21..1badd40f7f 100644
--- a/lib/spack/spack/cmd/arch.py
+++ b/lib/spack/spack/cmd/arch.py
@@ -22,10 +22,10 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import spack
 import spack.architecture as architecture
 
 description = "Print the architecture for this machine"
 
+
 def arch(parser, args):
     print architecture.sys_type()
diff --git a/lib/spack/spack/cmd/cd.py b/lib/spack/spack/cmd/cd.py
index aa45f67ae1..cf7232258c 100644
--- a/lib/spack/spack/cmd/cd.py
+++ b/lib/spack/spack/cmd/cd.py
@@ -25,7 +25,8 @@
 import spack.cmd.location
 import spack.modules
 
-description="cd to spack directories in the shell."
+description = "cd to spack directories in the shell."
+
 
 def setup_parser(subparser):
     """This is for decoration -- spack cd is used through spack's
diff --git a/lib/spack/spack/cmd/clean.py b/lib/spack/spack/cmd/clean.py
index 514c5874ef..dc62fbcaf6 100644
--- a/lib/spack/spack/cmd/clean.py
+++ b/lib/spack/spack/cmd/clean.py
@@ -31,6 +31,7 @@ import spack.cmd
 
 description = "Remove build stage and source tarball for packages."
 
+
 def setup_parser(subparser):
     subparser.add_argument('packages', nargs=argparse.REMAINDER,
                            help="specs of packages to clean")
diff --git a/lib/spack/spack/cmd/common/arguments.py b/lib/spack/spack/cmd/common/arguments.py
index af04170824..afcba33714 100644
--- a/lib/spack/spack/cmd/common/arguments.py
+++ b/lib/spack/spack/cmd/common/arguments.py
@@ -35,7 +35,7 @@ _arguments = {}
 def add_common_arguments(parser, list_of_arguments):
     for argument in list_of_arguments:
         if argument not in _arguments:
-            message = 'Trying to add the non existing argument "{0}" to a command'  # NOQA: ignore=E501
+            message = 'Trying to add non existing argument "{0}" to a command'
             raise KeyError(message.format(argument))
         x = _arguments[argument]
         parser.add_argument(*x.flags, **x.kwargs)
@@ -82,7 +82,7 @@ parms = Bunch(
     kwargs={
         'action': 'store_true',
         'dest': 'yes_to_all',
-        'help': 'Assume "yes" is the answer to every confirmation asked to the user.'  # NOQA: ignore=E501
+        'help': 'Assume "yes" is the answer to every confirmation request.'
     })
 _arguments['yes_to_all'] = parms
 
diff --git a/lib/spack/spack/cmd/compiler.py b/lib/spack/spack/cmd/compiler.py
index c325628ebf..ea91c71479 100644
--- a/lib/spack/spack/cmd/compiler.py
+++ b/lib/spack/spack/cmd/compiler.py
@@ -37,6 +37,7 @@ from spack.util.environment import get_path
 
 description = "Manage compilers"
 
+
 def setup_parser(subparser):
     sp = subparser.add_subparsers(
         metavar='SUBCOMMAND', dest='compiler_command')
@@ -44,48 +45,58 @@ def setup_parser(subparser):
     scopes = spack.config.config_scopes
 
     # Find
-    find_parser = sp.add_parser('find', aliases=['add'], help='Search the system for compilers to add to the Spack configuration.')
+    find_parser = sp.add_parser(
+        'find', aliases=['add'],
+        help='Search the system for compilers to add to Spack configuration.')
     find_parser.add_argument('add_paths', nargs=argparse.REMAINDER)
-    find_parser.add_argument('--scope', choices=scopes, default=spack.cmd.default_modify_scope,
-                            help="Configuration scope to modify.")
+    find_parser.add_argument(
+        '--scope', choices=scopes, default=spack.cmd.default_modify_scope,
+        help="Configuration scope to modify.")
 
     # Remove
-    remove_parser = sp.add_parser('remove', aliases=['rm'], help='Remove compiler by spec.')
+    remove_parser = sp.add_parser(
+        'remove', aliases=['rm'], help='Remove compiler by spec.')
     remove_parser.add_argument(
-        '-a', '--all', action='store_true', help='Remove ALL compilers that match spec.')
+        '-a', '--all', action='store_true',
+        help='Remove ALL compilers that match spec.')
     remove_parser.add_argument('compiler_spec')
-    remove_parser.add_argument('--scope', choices=scopes, default=spack.cmd.default_modify_scope,
-                               help="Configuration scope to modify.")
+    remove_parser.add_argument(
+        '--scope', choices=scopes, default=spack.cmd.default_modify_scope,
+        help="Configuration scope to modify.")
 
     # List
     list_parser = sp.add_parser('list', help='list available compilers')
-    list_parser.add_argument('--scope', choices=scopes, default=spack.cmd.default_list_scope,
-                             help="Configuration scope to read from.")
+    list_parser.add_argument(
+        '--scope', choices=scopes, default=spack.cmd.default_list_scope,
+        help="Configuration scope to read from.")
 
     # Info
     info_parser = sp.add_parser('info', help='Show compiler paths.')
     info_parser.add_argument('compiler_spec')
-    info_parser.add_argument('--scope', choices=scopes, default=spack.cmd.default_list_scope,
-                             help="Configuration scope to read from.")
+    info_parser.add_argument(
+        '--scope', choices=scopes, default=spack.cmd.default_list_scope,
+        help="Configuration scope to read from.")
 
 
 def compiler_find(args):
-    """Search either $PATH or a list of paths OR MODULES for compilers and add them
-       to Spack's configuration."""
+    """Search either $PATH or a list of paths OR MODULES for compilers and
+       add them to Spack's configuration.
+
+    """
     paths = args.add_paths
     if not paths:
         paths = get_path('PATH')
 
-    # Don't initialize compilers config via compilers.get_compiler_config. 
-    # Just let compiler_find do the 
+    # Don't initialize compilers config via compilers.get_compiler_config.
+    # Just let compiler_find do the
     # entire process and return an empty config from all_compilers
     # Default for any other process is init_config=True
     compilers = [c for c in spack.compilers.find_compilers(*paths)
                  if c.spec not in spack.compilers.all_compilers(
-                     scope=args.scope, init_config=False)] 
+                     scope=args.scope, init_config=False)]
     if compilers:
         spack.compilers.add_compilers_to_config(compilers, scope=args.scope,
-                init_config=False)
+                                                init_config=False)
         n = len(compilers)
         s = 's' if n > 1 else ''
         filename = spack.config.get_config_filename(args.scope, 'compilers')
@@ -103,11 +114,12 @@ def compiler_remove(args):
     elif not args.all and len(compilers) > 1:
         tty.error("Multiple compilers match spec %s. Choose one:" % cspec)
         colify(reversed(sorted([c.spec for c in compilers])), indent=4)
-        tty.msg("Or, you can use `spack compiler remove -a` to remove all of them.")
+        tty.msg("Or, use `spack compiler remove -a` to remove all of them.")
         sys.exit(1)
 
     for compiler in compilers:
-        spack.compilers.remove_compiler_from_config(compiler.spec, scope=args.scope)
+        spack.compilers.remove_compiler_from_config(
+            compiler.spec, scope=args.scope)
         tty.msg("Removed compiler %s" % compiler.spec)
 
 
@@ -133,7 +145,8 @@ def compiler_list(args):
     tty.msg("Available compilers")
     index = index_by(spack.compilers.all_compilers(scope=args.scope), 'name')
     for i, (name, compilers) in enumerate(index.items()):
-        if i >= 1: print
+        if i >= 1:
+            print
 
         cname = "%s{%s}" % (spack.spec.compiler_color, name)
         tty.hline(colorize(cname), char='-')
@@ -141,10 +154,10 @@ def compiler_list(args):
 
 
 def compiler(parser, args):
-    action = {'add'    : compiler_find, 
-              'find'   : compiler_find,
-              'remove' : compiler_remove,
-              'rm'     : compiler_remove,
-              'info'   : compiler_info,
-              'list'   : compiler_list }
+    action = {'add': compiler_find,
+              'find': compiler_find,
+              'remove': compiler_remove,
+              'rm': compiler_remove,
+              'info': compiler_info,
+              'list': compiler_list}
     action[args.compiler_command](args)
diff --git a/lib/spack/spack/cmd/compilers.py b/lib/spack/spack/cmd/compilers.py
index 9fbc2bb952..b87f977e5a 100644
--- a/lib/spack/spack/cmd/compilers.py
+++ b/lib/spack/spack/cmd/compilers.py
@@ -22,18 +22,16 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import llnl.util.tty as tty
-from llnl.util.tty.colify import colify
-from llnl.util.lang import index_by
-
 import spack
 from spack.cmd.compiler import compiler_list
 
 description = "List available compilers. Same as 'spack compiler list'."
 
+
 def setup_parser(subparser):
     subparser.add_argument('--scope', choices=spack.config.config_scopes,
                            help="Configuration scope to read/modify.")
 
+
 def compilers(parser, args):
     compiler_list(args)
diff --git a/lib/spack/spack/cmd/config.py b/lib/spack/spack/cmd/config.py
index d6f56c270d..c189e37036 100644
--- a/lib/spack/spack/cmd/config.py
+++ b/lib/spack/spack/cmd/config.py
@@ -22,15 +22,11 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import sys
-import argparse
-
-import llnl.util.tty as tty
-
 import spack.config
 
 description = "Get and set configuration options."
 
+
 def setup_parser(subparser):
     # User can only choose one
     scope_group = subparser.add_mutually_exclusive_group()
@@ -64,6 +60,6 @@ def config_edit(args):
 
 
 def config(parser, args):
-    action = { 'get' : config_get,
-               'edit' : config_edit }
+    action = {'get': config_get,
+              'edit': config_edit}
     action[args.config_command](args)
diff --git a/lib/spack/spack/cmd/create.py b/lib/spack/spack/cmd/create.py
index 51bf17a44b..52a82eb38f 100644
--- a/lib/spack/spack/cmd/create.py
+++ b/lib/spack/spack/cmd/create.py
@@ -217,6 +217,7 @@ def setup_parser(subparser):
 
 
 class BuildSystemGuesser(object):
+
     def __call__(self, stage, url):
         """Try to guess the type of build system used by a project based on
         the contents of its archive or the URL it was downloaded from."""
diff --git a/lib/spack/spack/cmd/deactivate.py b/lib/spack/spack/cmd/deactivate.py
index 990309ee48..2b15a0331e 100644
--- a/lib/spack/spack/cmd/deactivate.py
+++ b/lib/spack/spack/cmd/deactivate.py
@@ -31,6 +31,7 @@ from spack.graph import topological_sort
 
 description = "Deactivate a package extension."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-f', '--force', action='store_true',
@@ -40,7 +41,8 @@ def setup_parser(subparser):
         help="Deactivate all extensions of an extendable package, or "
         "deactivate an extension AND its dependencies.")
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="spec of package extension to deactivate.")
+        'spec', nargs=argparse.REMAINDER,
+        help="spec of package extension to deactivate.")
 
 
 def deactivate(parser, args):
@@ -65,7 +67,8 @@ def deactivate(parser, args):
             if not args.force and not spec.package.activated:
                 tty.die("%s is not activated." % pkg.spec.short_spec)
 
-            tty.msg("Deactivating %s and all dependencies." % pkg.spec.short_spec)
+            tty.msg("Deactivating %s and all dependencies." %
+                    pkg.spec.short_spec)
 
             topo_order = topological_sort(spec)
             index = spec.index()
@@ -79,7 +82,9 @@ def deactivate(parser, args):
                         epkg.do_deactivate(force=args.force)
 
         else:
-            tty.die("spack deactivate --all requires an extendable package or an extension.")
+            tty.die(
+                "spack deactivate --all requires an extendable package "
+                "or an extension.")
 
     else:
         if not pkg.is_extension:
diff --git a/lib/spack/spack/cmd/dependents.py b/lib/spack/spack/cmd/dependents.py
index 78eb6847b8..7729105e62 100644
--- a/lib/spack/spack/cmd/dependents.py
+++ b/lib/spack/spack/cmd/dependents.py
@@ -31,9 +31,11 @@ import spack.cmd
 
 description = "Show installed packages that depend on another."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="specs to list dependencies of.")
+        'spec', nargs=argparse.REMAINDER,
+        help="specs to list dependencies of.")
 
 
 def dependents(parser, args):
@@ -42,5 +44,6 @@ def dependents(parser, args):
         tty.die("spack dependents takes only one spec.")
 
     fmt = '$_$@$%@$+$=$#'
-    deps = [d.format(fmt, color=True) for d in specs[0].package.installed_dependents]
+    deps = [d.format(fmt, color=True)
+            for d in specs[0].package.installed_dependents]
     tty.msg("Dependents of %s" % specs[0].format(fmt, color=True), *deps)
diff --git a/lib/spack/spack/cmd/diy.py b/lib/spack/spack/cmd/diy.py
index 643e6374b2..487654d261 100644
--- a/lib/spack/spack/cmd/diy.py
+++ b/lib/spack/spack/cmd/diy.py
@@ -35,6 +35,7 @@ from spack.stage import DIYStage
 
 description = "Do-It-Yourself: build from an existing source directory."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-i', '--ignore-dependencies', action='store_true', dest='ignore_deps',
@@ -76,14 +77,17 @@ def diy(self, args):
                 return
 
         if not spec.versions.concrete:
-            tty.die("spack diy spec must have a single, concrete version.  Did you forget a package version number?")
+            tty.die(
+                "spack diy spec must have a single, concrete version. "
+                "Did you forget a package version number?")
 
         spec.concretize()
         package = spack.repo.get(spec)
 
         if package.installed:
             tty.error("Already installed in %s" % package.prefix)
-            tty.msg("Uninstall or try adding a version suffix for this DIY build.")
+            tty.msg("Uninstall or try adding a version suffix for this "
+                    "DIY build.")
             sys.exit(1)
 
         # Forces the build to run out of the current directory.
diff --git a/lib/spack/spack/cmd/doc.py b/lib/spack/spack/cmd/doc.py
index b3d0737d13..291b17216f 100644
--- a/lib/spack/spack/cmd/doc.py
+++ b/lib/spack/spack/cmd/doc.py
@@ -25,6 +25,7 @@
 
 description = "Run pydoc from within spack."
 
+
 def setup_parser(subparser):
     subparser.add_argument('entity', help="Run pydoc help on entity")
 
diff --git a/lib/spack/spack/cmd/edit.py b/lib/spack/spack/cmd/edit.py
index 49ab83867a..286136dd67 100644
--- a/lib/spack/spack/cmd/edit.py
+++ b/lib/spack/spack/cmd/edit.py
@@ -68,7 +68,7 @@ def edit_package(name, repo_path, namespace, force=False):
     if os.path.exists(path):
         if not os.path.isfile(path):
             tty.die("Something's wrong.  '%s' is not a file!" % path)
-        if not os.access(path, os.R_OK|os.W_OK):
+        if not os.access(path, os.R_OK | os.W_OK):
             tty.die("Insufficient permissions on '%s'!" % path)
     elif not force:
         tty.die("No package '%s'.  Use spack create, or supply -f/--force "
@@ -93,19 +93,23 @@ def setup_parser(subparser):
     # Various filetypes you can edit directly from the cmd line.
     excl_args.add_argument(
         '-c', '--command', dest='path', action='store_const',
-        const=spack.cmd.command_path, help="Edit the command with the supplied name.")
+        const=spack.cmd.command_path,
+        help="Edit the command with the supplied name.")
     excl_args.add_argument(
         '-t', '--test', dest='path', action='store_const',
         const=spack.test_path, help="Edit the test with the supplied name.")
     excl_args.add_argument(
         '-m', '--module', dest='path', action='store_const',
-        const=spack.module_path, help="Edit the main spack module with the supplied name.")
+        const=spack.module_path,
+        help="Edit the main spack module with the supplied name.")
 
     # Options for editing packages
     excl_args.add_argument(
-        '-r', '--repo', default=None, help="Path to repo to edit package in.")
+        '-r', '--repo', default=None,
+        help="Path to repo to edit package in.")
     excl_args.add_argument(
-        '-N', '--namespace', default=None, help="Namespace of package to edit.")
+        '-N', '--namespace', default=None,
+        help="Namespace of package to edit.")
 
     subparser.add_argument(
         'name', nargs='?', default=None, help="name of package to edit")
diff --git a/lib/spack/spack/cmd/env.py b/lib/spack/spack/cmd/env.py
index 85d111e91e..f3bad039d4 100644
--- a/lib/spack/spack/cmd/env.py
+++ b/lib/spack/spack/cmd/env.py
@@ -28,11 +28,13 @@ import llnl.util.tty as tty
 import spack.cmd
 import spack.build_environment as build_env
 
-description = "Run a command with the environment for a particular spec's install."
+description = "Run a command with the install environment for a spec."
+
 
 def setup_parser(subparser):
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="specs of package environment to emulate.")
+        'spec', nargs=argparse.REMAINDER,
+        help="specs of package environment to emulate.")
 
 
 def env(parser, args):
@@ -47,7 +49,7 @@ def env(parser, args):
     if sep in args.spec:
         s = args.spec.index(sep)
         spec = args.spec[:s]
-        cmd  = args.spec[s+1:]
+        cmd  = args.spec[s + 1:]
     else:
         spec = args.spec[0]
         cmd  = args.spec[1:]
diff --git a/lib/spack/spack/cmd/extensions.py b/lib/spack/spack/cmd/extensions.py
index 11659e0c96..b5c484305f 100644
--- a/lib/spack/spack/cmd/extensions.py
+++ b/lib/spack/spack/cmd/extensions.py
@@ -22,7 +22,6 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import sys
 import argparse
 
 import llnl.util.tty as tty
@@ -34,6 +33,7 @@ import spack.cmd.find
 
 description = "List extensions for package."
 
+
 def setup_parser(subparser):
     format_group = subparser.add_mutually_exclusive_group()
     format_group.add_argument(
@@ -47,7 +47,8 @@ def setup_parser(subparser):
         help='Show full dependency DAG of extensions')
 
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help='Spec of package to list extensions for')
+        'spec', nargs=argparse.REMAINDER,
+        help='Spec of package to list extensions for')
 
 
 def extensions(parser, args):
@@ -85,7 +86,8 @@ def extensions(parser, args):
     #
     # List specs of installed extensions.
     #
-    installed = [s.spec for s in spack.installed_db.installed_extensions_for(spec)]
+    installed = [
+        s.spec for s in spack.installed_db.installed_extensions_for(spec)]
     print
     if not installed:
         tty.msg("None installed.")
@@ -102,4 +104,5 @@ def extensions(parser, args):
         tty.msg("None activated.")
         return
     tty.msg("%d currently activated:" % len(activated))
-    spack.cmd.find.display_specs(activated.values(), mode=args.mode, long=args.long)
+    spack.cmd.find.display_specs(
+        activated.values(), mode=args.mode, long=args.long)
diff --git a/lib/spack/spack/cmd/fetch.py b/lib/spack/spack/cmd/fetch.py
index 1afc51d9fa..c1ac2ed48d 100644
--- a/lib/spack/spack/cmd/fetch.py
+++ b/lib/spack/spack/cmd/fetch.py
@@ -29,16 +29,21 @@ import spack.cmd
 
 description = "Fetch archives for packages"
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-n', '--no-checksum', action='store_true', dest='no_checksum',
         help="Do not check packages against checksum")
     subparser.add_argument(
-        '-m', '--missing', action='store_true', help="Also fetch all missing dependencies")
+        '-m', '--missing', action='store_true',
+        help="Also fetch all missing dependencies")
     subparser.add_argument(
-        '-D', '--dependencies', action='store_true', help="Also fetch all dependencies")
+        '-D', '--dependencies', action='store_true',
+        help="Also fetch all dependencies")
     subparser.add_argument(
-        'packages', nargs=argparse.REMAINDER, help="specs of packages to fetch")
+        'packages', nargs=argparse.REMAINDER,
+        help="specs of packages to fetch")
+
 
 def fetch(parser, args):
     if not args.packages:
@@ -50,7 +55,6 @@ def fetch(parser, args):
     specs = spack.cmd.parse_specs(args.packages, concretize=True)
     for spec in specs:
         if args.missing or args.dependencies:
-            to_fetch = set()
             for s in spec.traverse(deptype_query=spack.alldeps):
                 package = spack.repo.get(s)
                 if args.missing and package.installed:
diff --git a/lib/spack/spack/cmd/graph.py b/lib/spack/spack/cmd/graph.py
index da65121836..8faabfbb7b 100644
--- a/lib/spack/spack/cmd/graph.py
+++ b/lib/spack/spack/cmd/graph.py
@@ -30,6 +30,7 @@ from spack.graph import *
 
 description = "Generate graphs of package dependency relationships."
 
+
 def setup_parser(subparser):
     setup_parser.parser = subparser
 
@@ -42,10 +43,12 @@ def setup_parser(subparser):
         help="Generate graph in dot format and print to stdout.")
 
     subparser.add_argument(
-        '--concretize', action='store_true', help="Concretize specs before graphing.")
+        '--concretize', action='store_true',
+        help="Concretize specs before graphing.")
 
     subparser.add_argument(
-        'specs', nargs=argparse.REMAINDER, help="specs of packages to graph.")
+        'specs', nargs=argparse.REMAINDER,
+        help="specs of packages to graph.")
 
 
 def graph(parser, args):
@@ -56,11 +59,11 @@ def graph(parser, args):
         setup_parser.parser.print_help()
         return 1
 
-    if args.dot:    # Dot graph only if asked for.
+    if args.dot:  # Dot graph only if asked for.
         graph_dot(*specs)
 
-    elif specs:     # ascii is default: user doesn't need to provide it explicitly
+    elif specs:  # ascii is default: user doesn't need to provide it explicitly
         graph_ascii(specs[0], debug=spack.debug)
         for spec in specs[1:]:
-            print # extra line bt/w independent graphs
+            print  # extra line bt/w independent graphs
             graph_ascii(spec, debug=spack.debug)
diff --git a/lib/spack/spack/cmd/help.py b/lib/spack/spack/cmd/help.py
index 1d23161839..5bc8fc3e74 100644
--- a/lib/spack/spack/cmd/help.py
+++ b/lib/spack/spack/cmd/help.py
@@ -22,14 +22,14 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import sys
-
 description = "Get help on spack and its commands"
 
+
 def setup_parser(subparser):
     subparser.add_argument('help_command', nargs='?', default=None,
                            help='command to get help on')
 
+
 def help(parser, args):
     if args.help_command:
         parser.parse_args([args.help_command, '-h'])
diff --git a/lib/spack/spack/cmd/install.py b/lib/spack/spack/cmd/install.py
index 4c076322a9..7663a97a28 100644
--- a/lib/spack/spack/cmd/install.py
+++ b/lib/spack/spack/cmd/install.py
@@ -31,6 +31,7 @@ import spack.cmd
 
 description = "Build and install packages"
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-i', '--ignore-dependencies', action='store_true', dest='ignore_deps',
@@ -52,18 +53,18 @@ def setup_parser(subparser):
         help="Display verbose build output while installing.")
     subparser.add_argument(
         '--fake', action='store_true', dest='fake',
-        help="Fake install.  Just remove the prefix and touch a fake file in it.")
+        help="Fake install. Just remove prefix and create a fake file.")
     subparser.add_argument(
         '--dirty', action='store_true', dest='dirty',
         help="Install a package *without* cleaning the environment.")
     subparser.add_argument(
-        'packages', nargs=argparse.REMAINDER, help="specs of packages to install")
+        'packages', nargs=argparse.REMAINDER,
+        help="specs of packages to install")
     subparser.add_argument(
         '--run-tests', action='store_true', dest='run_tests',
         help="Run tests during installation of a package.")
 
 
-
 def install(parser, args):
     if not args.packages:
         tty.die("install requires at least one package argument")
diff --git a/lib/spack/spack/cmd/load.py b/lib/spack/spack/cmd/load.py
index 205abbb6b3..85190a5d0b 100644
--- a/lib/spack/spack/cmd/load.py
+++ b/lib/spack/spack/cmd/load.py
@@ -25,13 +25,16 @@
 import argparse
 import spack.modules
 
-description ="Add package to environment using modules."
+description = "Add package to environment using modules."
+
 
 def setup_parser(subparser):
     """Parser is only constructed so that this prints a nice help
        message with -h. """
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="Spec of package to load with modules.  (If -, read specs from STDIN)")
+        'spec', nargs=argparse.REMAINDER,
+        help="Spec of package to load with modules. "
+             "(If -, read specs from STDIN)")
 
 
 def load(parser, args):
diff --git a/lib/spack/spack/cmd/location.py b/lib/spack/spack/cmd/location.py
index b0dbb1a550..b9c8b5c330 100644
--- a/lib/spack/spack/cmd/location.py
+++ b/lib/spack/spack/cmd/location.py
@@ -22,8 +22,6 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import os
-import sys
 import argparse
 
 import llnl.util.tty as tty
@@ -32,16 +30,19 @@ from llnl.util.filesystem import join_path
 import spack
 import spack.cmd
 
-description="Print out locations of various directories used by Spack"
+description = "Print out locations of various directories used by Spack"
+
 
 def setup_parser(subparser):
     global directories
     directories = subparser.add_mutually_exclusive_group()
 
     directories.add_argument(
-        '-m', '--module-dir', action='store_true', help="Spack python module directory.")
+        '-m', '--module-dir', action='store_true',
+        help="Spack python module directory.")
     directories.add_argument(
-        '-r', '--spack-root', action='store_true', help="Spack installation root.")
+        '-r', '--spack-root', action='store_true',
+        help="Spack installation root.")
 
     directories.add_argument(
         '-i', '--install-dir', action='store_true',
@@ -53,15 +54,19 @@ def setup_parser(subparser):
         '-P', '--packages', action='store_true',
         help="Top-level packages directory for Spack.")
     directories.add_argument(
-        '-s', '--stage-dir', action='store_true', help="Stage directory for a spec.")
+        '-s', '--stage-dir', action='store_true',
+        help="Stage directory for a spec.")
     directories.add_argument(
-        '-S', '--stages', action='store_true', help="Top level Stage directory.")
+        '-S', '--stages', action='store_true',
+        help="Top level Stage directory.")
     directories.add_argument(
         '-b', '--build-dir', action='store_true',
-        help="Checked out or expanded source directory for a spec (requires it to be staged first).")
+        help="Checked out or expanded source directory for a spec "
+             "(requires it to be staged first).")
 
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help="spec of package to fetch directory for.")
+        'spec', nargs=argparse.REMAINDER,
+        help="spec of package to fetch directory for.")
 
 
 def location(parser, args):
@@ -104,9 +109,9 @@ def location(parser, args):
                 if args.stage_dir:
                     print pkg.stage.path
 
-                else:  #  args.build_dir is the default.
+                else:  # args.build_dir is the default.
                     if not pkg.stage.source_path:
-                        tty.die("Build directory does not exist yet. Run this to create it:",
+                        tty.die("Build directory does not exist yet. "
+                                "Run this to create it:",
                                 "spack stage " + " ".join(args.spec))
                     print pkg.stage.source_path
-
diff --git a/lib/spack/spack/cmd/mirror.py b/lib/spack/spack/cmd/mirror.py
index 0cf682fc4f..585faaf524 100644
--- a/lib/spack/spack/cmd/mirror.py
+++ b/lib/spack/spack/cmd/mirror.py
@@ -23,7 +23,6 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import os
-import sys
 from datetime import datetime
 
 import argparse
@@ -40,6 +39,7 @@ from spack.util.spack_yaml import syaml_dict
 
 description = "Manage mirrors."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-n', '--no-checksum', action='store_true', dest='no_checksum',
@@ -61,8 +61,9 @@ def setup_parser(subparser):
         '-D', '--dependencies', action='store_true',
         help="Also fetch all dependencies")
     create_parser.add_argument(
-        '-o', '--one-version-per-spec', action='store_const', const=1, default=0,
-        help="Only fetch one 'preferred' version per spec, not all known versions.")
+        '-o', '--one-version-per-spec', action='store_const',
+        const=1, default=0,
+        help="Only fetch one 'preferred' version per spec, not all known.")
 
     scopes = spack.config.config_scopes
 
@@ -70,7 +71,7 @@ def setup_parser(subparser):
     add_parser = sp.add_parser('add', help=mirror_add.__doc__)
     add_parser.add_argument('name', help="Mnemonic name for mirror.")
     add_parser.add_argument(
-        'url', help="URL of mirror directory created by 'spack mirror create'.")
+        'url', help="URL of mirror directory from 'spack mirror create'.")
     add_parser.add_argument(
         '--scope', choices=scopes, default=spack.cmd.default_modify_scope,
         help="Configuration scope to modify.")
@@ -107,7 +108,7 @@ def mirror_add(args):
             tty.die("Mirror with url %s already exists." % url)
         # should only be one item per mirror dict.
 
-    items = [(n,u) for n,u in mirrors.items()]
+    items = [(n, u) for n, u in mirrors.items()]
     items.insert(0, (args.name, url))
     mirrors = syaml_dict(items)
     spack.config.update_config('mirrors', mirrors, scope=args.scope)
@@ -121,7 +122,7 @@ def mirror_remove(args):
     if not mirrors:
         mirrors = syaml_dict()
 
-    if not name in mirrors:
+    if name not in mirrors:
         tty.die("No mirror with name %s" % name)
 
     old_value = mirrors.pop(name)
@@ -152,7 +153,7 @@ def _read_specs_from_file(filename):
                 s.package
                 specs.append(s)
             except SpackError, e:
-                tty.die("Parse error in %s, line %d:" % (args.file, i+1),
+                tty.die("Parse error in %s, line %d:" % (args.file, i + 1),
                         ">>> " + string, str(e))
     return specs
 
@@ -214,10 +215,10 @@ def mirror_create(args):
 
 
 def mirror(parser, args):
-    action = { 'create' : mirror_create,
-               'add'    : mirror_add,
-               'remove' : mirror_remove,
-               'rm'     : mirror_remove,
-               'list'   : mirror_list }
+    action = {'create': mirror_create,
+              'add': mirror_add,
+              'remove': mirror_remove,
+              'rm': mirror_remove,
+              'list': mirror_list}
 
     action[args.mirror_command](args)
diff --git a/lib/spack/spack/cmd/module.py b/lib/spack/spack/cmd/module.py
index a10e36e077..2d0b83fe00 100644
--- a/lib/spack/spack/cmd/module.py
+++ b/lib/spack/spack/cmd/module.py
@@ -118,7 +118,8 @@ def loads(mtype, specs, args):
         seen_add = seen.add
         for spec in specs_from_user_constraint:
             specs.extend(
-                [item for item in spec.traverse(order='post', cover='nodes') if not (item in seen or seen_add(item))]  # NOQA: ignore=E501
+                [item for item in spec.traverse(order='post', cover='nodes')
+                 if not (item in seen or seen_add(item))]
             )
 
     module_cls = module_types[mtype]
@@ -178,7 +179,9 @@ def rm(mtype, specs, args):
 
     # Ask for confirmation
     if not args.yes_to_all:
-        tty.msg('You are about to remove {0} module files the following specs:\n'.format(mtype))  # NOQA: ignore=E501
+        tty.msg(
+            'You are about to remove {0} module files the following specs:\n'
+            .format(mtype))
         spack.cmd.display_specs(specs_with_modules, long=True)
         print('')
         spack.cmd.ask_for_confirmation('Do you want to proceed ? ')
@@ -197,7 +200,9 @@ def refresh(mtype, specs, args):
         return
 
     if not args.yes_to_all:
-        tty.msg('You are about to regenerate {name} module files for the following specs:\n'.format(name=mtype))  # NOQA: ignore=E501
+        tty.msg(
+            'You are about to regenerate {name} module files for:\n'
+            .format(name=mtype))
         spack.cmd.display_specs(specs, long=True)
         print('')
         spack.cmd.ask_for_confirmation('Do you want to proceed ? ')
@@ -245,11 +250,13 @@ def module(parser, args):
     try:
         callbacks[args.subparser_name](module_type, args.specs, args)
     except MultipleMatches:
-        message = 'the constraint \'{query}\' matches multiple packages, and this is not allowed in this context'  # NOQA: ignore=E501
+        message = ('the constraint \'{query}\' matches multiple packages, '
+                   'and this is not allowed in this context')
         tty.error(message.format(query=constraint))
         for s in args.specs:
             sys.stderr.write(s.format(color=True) + '\n')
         raise SystemExit(1)
     except NoMatch:
-        message = 'the constraint \'{query}\' match no package, and this is not allowed in this context'  # NOQA: ignore=E501
+        message = ('the constraint \'{query}\' match no package, '
+                   'and this is not allowed in this context')
         tty.die(message.format(query=constraint))
diff --git a/lib/spack/spack/cmd/package-list.py b/lib/spack/spack/cmd/package-list.py
index a27502d30e..9ed42de823 100644
--- a/lib/spack/spack/cmd/package-list.py
+++ b/lib/spack/spack/cmd/package-list.py
@@ -32,7 +32,7 @@ description = "Print a list of all packages in reStructuredText."
 
 def github_url(pkg):
     """Link to a package file on github."""
-    url = "https://github.com/llnl/spack/blob/master/var/spack/packages/%s/package.py"  # NOQA: ignore=E501
+    url = "https://github.com/llnl/spack/blob/master/var/spack/packages/%s/package.py"
     return (url % pkg.name)
 
 
diff --git a/lib/spack/spack/cmd/patch.py b/lib/spack/spack/cmd/patch.py
index a5507e42cf..9c72da40b5 100644
--- a/lib/spack/spack/cmd/patch.py
+++ b/lib/spack/spack/cmd/patch.py
@@ -29,14 +29,16 @@ import spack.cmd
 import spack
 
 
-description="Patch expanded archive sources in preparation for install"
+description = "Patch expanded archive sources in preparation for install"
+
 
 def setup_parser(subparser):
     subparser.add_argument(
         '-n', '--no-checksum', action='store_true', dest='no_checksum',
         help="Do not check downloaded packages against checksum")
     subparser.add_argument(
-        'packages', nargs=argparse.REMAINDER, help="specs of packages to stage")
+        'packages', nargs=argparse.REMAINDER,
+        help="specs of packages to stage")
 
 
 def patch(parser, args):
diff --git a/lib/spack/spack/cmd/pkg.py b/lib/spack/spack/cmd/pkg.py
index a24c2759fe..7791b93cf5 100644
--- a/lib/spack/spack/cmd/pkg.py
+++ b/lib/spack/spack/cmd/pkg.py
@@ -33,6 +33,7 @@ from spack.util.executable import *
 
 description = "Query packages associated with particular git revisions."
 
+
 def setup_parser(subparser):
     sp = subparser.add_subparsers(
         metavar='SUBCOMMAND', dest='pkg_command')
@@ -46,22 +47,28 @@ def setup_parser(subparser):
                              help="Revision to list packages for.")
 
     diff_parser = sp.add_parser('diff', help=pkg_diff.__doc__)
-    diff_parser.add_argument('rev1', nargs='?', default='HEAD^',
-                             help="Revision to compare against.")
-    diff_parser.add_argument('rev2', nargs='?', default='HEAD',
-                             help="Revision to compare to rev1 (default is HEAD).")
+    diff_parser.add_argument(
+        'rev1', nargs='?', default='HEAD^',
+        help="Revision to compare against.")
+    diff_parser.add_argument(
+        'rev2', nargs='?', default='HEAD',
+        help="Revision to compare to rev1 (default is HEAD).")
 
     add_parser = sp.add_parser('added', help=pkg_added.__doc__)
-    add_parser.add_argument('rev1', nargs='?', default='HEAD^',
-                             help="Revision to compare against.")
-    add_parser.add_argument('rev2', nargs='?', default='HEAD',
-                            help="Revision to compare to rev1 (default is HEAD).")
+    add_parser.add_argument(
+        'rev1', nargs='?', default='HEAD^',
+        help="Revision to compare against.")
+    add_parser.add_argument(
+        'rev2', nargs='?', default='HEAD',
+        help="Revision to compare to rev1 (default is HEAD).")
 
     rm_parser = sp.add_parser('removed', help=pkg_removed.__doc__)
-    rm_parser.add_argument('rev1', nargs='?', default='HEAD^',
-                           help="Revision to compare against.")
-    rm_parser.add_argument('rev2', nargs='?', default='HEAD',
-                           help="Revision to compare to rev1 (default is HEAD).")
+    rm_parser.add_argument(
+        'rev1', nargs='?', default='HEAD^',
+        help="Revision to compare against.")
+    rm_parser.add_argument(
+        'rev2', nargs='?', default='HEAD',
+        help="Revision to compare to rev1 (default is HEAD).")
 
 
 def get_git():
@@ -88,7 +95,8 @@ def pkg_add(args):
     for pkg_name in args.packages:
         filename = spack.repo.filename_for_package_name(pkg_name)
         if not os.path.isfile(filename):
-            tty.die("No such package: %s.  Path does not exist:" % pkg_name, filename)
+            tty.die("No such package: %s.  Path does not exist:" %
+                    pkg_name, filename)
 
         git = get_git()
         git('-C', spack.packages_path, 'add', filename)
@@ -112,7 +120,8 @@ def pkg_diff(args):
     if u1:
         print "%s:" % args.rev1
         colify(sorted(u1), indent=4)
-        if u1: print
+        if u1:
+            print
 
     if u2:
         print "%s:" % args.rev2
@@ -122,19 +131,21 @@ def pkg_diff(args):
 def pkg_removed(args):
     """Show packages removed since a commit."""
     u1, u2 = diff_packages(args.rev1, args.rev2)
-    if u1: colify(sorted(u1))
+    if u1:
+        colify(sorted(u1))
 
 
 def pkg_added(args):
     """Show packages added since a commit."""
     u1, u2 = diff_packages(args.rev1, args.rev2)
-    if u2: colify(sorted(u2))
+    if u2:
+        colify(sorted(u2))
 
 
 def pkg(parser, args):
-    action = { 'add'    : pkg_add,
-               'diff'    : pkg_diff,
-               'list'    : pkg_list,
-               'removed' : pkg_removed,
-               'added'   : pkg_added }
+    action = {'add': pkg_add,
+              'diff': pkg_diff,
+              'list': pkg_list,
+              'removed': pkg_removed,
+              'added': pkg_added}
     action[args.pkg_command](args)
diff --git a/lib/spack/spack/cmd/providers.py b/lib/spack/spack/cmd/providers.py
index e9007486d2..0f4a97cc4a 100644
--- a/lib/spack/spack/cmd/providers.py
+++ b/lib/spack/spack/cmd/providers.py
@@ -22,7 +22,6 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import os
 import argparse
 
 from llnl.util.tty.colify import colify
@@ -30,11 +29,13 @@ from llnl.util.tty.colify import colify
 import spack
 import spack.cmd
 
-description ="List packages that provide a particular virtual package"
+description = "List packages that provide a particular virtual package"
+
 
 def setup_parser(subparser):
-    subparser.add_argument('vpkg_spec', metavar='VPACKAGE_SPEC', nargs=argparse.REMAINDER,
-                           help='Find packages that provide this virtual package')
+    subparser.add_argument(
+        'vpkg_spec', metavar='VPACKAGE_SPEC', nargs=argparse.REMAINDER,
+        help='Find packages that provide this virtual package')
 
 
 def providers(parser, args):
diff --git a/lib/spack/spack/cmd/python.py b/lib/spack/spack/cmd/python.py
index 59423271b9..12727cb599 100644
--- a/lib/spack/spack/cmd/python.py
+++ b/lib/spack/spack/cmd/python.py
@@ -30,18 +30,22 @@ import platform
 
 import spack
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-c', dest='python_command', help='Command to execute.')
     subparser.add_argument(
-        'python_args', nargs=argparse.REMAINDER, help="File to run plus arguments.")
+        'python_args', nargs=argparse.REMAINDER,
+        help="File to run plus arguments.")
+
 
 description = "Launch an interpreter as spack would launch a command"
 
+
 def python(parser, args):
     # Fake a main python shell by setting __name__ to __main__.
-    console = code.InteractiveConsole({'__name__' : '__main__',
-                                       'spack'    : spack})
+    console = code.InteractiveConsole({'__name__': '__main__',
+                                       'spack': spack})
 
     if "PYTHONSTARTUP" in os.environ:
         startup_file = os.environ["PYTHONSTARTUP"]
diff --git a/lib/spack/spack/cmd/reindex.py b/lib/spack/spack/cmd/reindex.py
index 93eba7a0f1..e37eebbd92 100644
--- a/lib/spack/spack/cmd/reindex.py
+++ b/lib/spack/spack/cmd/reindex.py
@@ -22,10 +22,10 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import argparse
 import spack
 
 description = "Rebuild Spack's package database."
 
+
 def reindex(parser, args):
     spack.installed_db.reindex(spack.install_layout)
diff --git a/lib/spack/spack/cmd/repo.py b/lib/spack/spack/cmd/repo.py
index cbd8f4784e..5ab2ac0833 100644
--- a/lib/spack/spack/cmd/repo.py
+++ b/lib/spack/spack/cmd/repo.py
@@ -23,20 +23,16 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import os
-import re
-import shutil
 
-import argparse
 import llnl.util.tty as tty
-from llnl.util.filesystem import join_path, mkdirp
 
 import spack.spec
 import spack.config
-from spack.util.environment import get_path
 from spack.repository import *
 
 description = "Manage package source repositories."
 
+
 def setup_parser(subparser):
     sp = subparser.add_subparsers(metavar='SUBCOMMAND', dest='repo_command')
     scopes = spack.config.config_scopes
@@ -57,13 +53,15 @@ def setup_parser(subparser):
 
     # Add
     add_parser = sp.add_parser('add', help=repo_add.__doc__)
-    add_parser.add_argument('path', help="Path to a Spack package repository directory.")
+    add_parser.add_argument(
+        'path', help="Path to a Spack package repository directory.")
     add_parser.add_argument(
         '--scope', choices=scopes, default=spack.cmd.default_modify_scope,
         help="Configuration scope to modify.")
 
     # Remove
-    remove_parser = sp.add_parser('remove', help=repo_remove.__doc__, aliases=['rm'])
+    remove_parser = sp.add_parser(
+        'remove', help=repo_remove.__doc__, aliases=['rm'])
     remove_parser.add_argument(
         'path_or_namespace',
         help="Path or namespace of a Spack package repository.")
@@ -100,7 +98,8 @@ def repo_add(args):
 
     # If that succeeds, finally add it to the configuration.
     repos = spack.config.get_config('repos', args.scope)
-    if not repos: repos = []
+    if not repos:
+        repos = []
 
     if repo.root in repos or path in repos:
         tty.die("Repository is already registered with Spack: %s" % path)
@@ -135,7 +134,7 @@ def repo_remove(args):
                 tty.msg("Removed repository %s with namespace '%s'."
                         % (repo.root, repo.namespace))
                 return
-        except RepoError as e:
+        except RepoError:
             continue
 
     tty.die("No repository with path or namespace: %s"
@@ -149,7 +148,7 @@ def repo_list(args):
     for r in roots:
         try:
             repos.append(Repo(r))
-        except RepoError as e:
+        except RepoError:
             continue
 
     msg = "%d package repositor" % len(repos)
@@ -166,9 +165,9 @@ def repo_list(args):
 
 
 def repo(parser, args):
-    action = { 'create' : repo_create,
-               'list'   : repo_list,
-               'add'    : repo_add,
-               'remove' : repo_remove,
-               'rm'     : repo_remove}
+    action = {'create': repo_create,
+              'list': repo_list,
+              'add': repo_add,
+              'remove': repo_remove,
+              'rm': repo_remove}
     action[args.repo_command](args)
diff --git a/lib/spack/spack/cmd/restage.py b/lib/spack/spack/cmd/restage.py
index 325d30662f..969afe09bd 100644
--- a/lib/spack/spack/cmd/restage.py
+++ b/lib/spack/spack/cmd/restage.py
@@ -31,6 +31,7 @@ import spack.cmd
 
 description = "Revert checked out package source code."
 
+
 def setup_parser(subparser):
     subparser.add_argument('packages', nargs=argparse.REMAINDER,
                            help="specs of packages to restage")
diff --git a/lib/spack/spack/cmd/setup.py b/lib/spack/spack/cmd/setup.py
index 04f3d663df..b55e102c0e 100644
--- a/lib/spack/spack/cmd/setup.py
+++ b/lib/spack/spack/cmd/setup.py
@@ -35,6 +35,7 @@ from spack.stage import DIYStage
 
 description = "Create a configuration script and module, but don't build."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-i', '--ignore-dependencies', action='store_true', dest='ignore_deps',
@@ -70,7 +71,9 @@ def setup(self, args):
                 return
 
         if not spec.versions.concrete:
-            tty.die("spack setup spec must have a single, concrete version.  Did you forget a package version number?")
+            tty.die(
+                "spack setup spec must have a single, concrete version. "
+                "Did you forget a package version number?")
 
         spec.concretize()
         package = spack.repo.get(spec)
@@ -84,8 +87,8 @@ def setup(self, args):
         spack.do_checksum = False
 
         package.do_install(
-            keep_prefix=True,        # Don't remove install directory, even if you think you should
+            keep_prefix=True,  # Don't remove install directory
             ignore_deps=args.ignore_deps,
             verbose=args.verbose,
             keep_stage=True,   # don't remove source dir for SETUP.
-            install_phases = set(['setup', 'provenance']))
+            install_phases=set(['setup', 'provenance']))
diff --git a/lib/spack/spack/cmd/spec.py b/lib/spack/spack/cmd/spec.py
index 321e3e429b..6e6d1c1277 100644
--- a/lib/spack/spack/cmd/spec.py
+++ b/lib/spack/spack/cmd/spec.py
@@ -25,23 +25,22 @@
 import argparse
 import spack.cmd
 
-import llnl.util.tty as tty
-
 import spack
-import spack.url as url
 
 description = "print out abstract and concrete versions of a spec."
 
+
 def setup_parser(subparser):
     subparser.add_argument('-i', '--ids', action='store_true',
                            help="show numerical ids for dependencies.")
-    subparser.add_argument('specs', nargs=argparse.REMAINDER, help="specs of packages")
+    subparser.add_argument(
+        'specs', nargs=argparse.REMAINDER, help="specs of packages")
 
 
 def spec(parser, args):
-    kwargs = { 'ids'    : args.ids,
-               'indent' : 2,
-               'color'  : True }
+    kwargs = {'ids': args.ids,
+              'indent': 2,
+              'color': True}
 
     for spec in spack.cmd.parse_specs(args.specs):
         print "Input spec"
diff --git a/lib/spack/spack/cmd/stage.py b/lib/spack/spack/cmd/stage.py
index 61e9c6d9ff..bfc2e5f456 100644
--- a/lib/spack/spack/cmd/stage.py
+++ b/lib/spack/spack/cmd/stage.py
@@ -22,14 +22,14 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import os
 import argparse
 
 import llnl.util.tty as tty
 import spack
 import spack.cmd
 
-description="Expand downloaded archive in preparation for install"
+description = "Expand downloaded archive in preparation for install"
+
 
 def setup_parser(subparser):
     subparser.add_argument(
diff --git a/lib/spack/spack/cmd/test-install.py b/lib/spack/spack/cmd/test-install.py
index 14c06d136d..8e7173e9a2 100644
--- a/lib/spack/spack/cmd/test-install.py
+++ b/lib/spack/spack/cmd/test-install.py
@@ -36,25 +36,25 @@ from llnl.util.filesystem import *
 from spack.build_environment import InstallError
 from spack.fetch_strategy import FetchError
 
-description = "Run package installation as a unit test, output formatted results."
+description = "Run package install as a unit test, output formatted results."
 
 
 def setup_parser(subparser):
-    subparser.add_argument('-j',
-                           '--jobs',
-                           action='store',
-                           type=int,
-                           help="Explicitly set number of make jobs.  Default is #cpus.")
+    subparser.add_argument(
+        '-j', '--jobs', action='store', type=int,
+        help="Explicitly set number of make jobs.  Default is #cpus.")
 
-    subparser.add_argument('-n',
-                           '--no-checksum',
-                           action='store_true',
-                           dest='no_checksum',
-                           help="Do not check packages against checksum")
+    subparser.add_argument(
+        '-n', '--no-checksum', action='store_true', dest='no_checksum',
+        help="Do not check packages against checksum")
 
-    subparser.add_argument('-o', '--output', action='store', help="test output goes in this file")
+    subparser.add_argument(
+        '-o', '--output', action='store',
+        help="test output goes in this file")
 
-    subparser.add_argument('package', nargs=argparse.REMAINDER, help="spec of package to install")
+    subparser.add_argument(
+        'package', nargs=argparse.REMAINDER,
+        help="spec of package to install")
 
 
 class TestResult(object):
@@ -65,6 +65,7 @@ class TestResult(object):
 
 
 class TestSuite(object):
+
     def __init__(self, filename):
         self.filename = filename
         self.root = ET.Element('testsuite')
@@ -75,14 +76,17 @@ class TestSuite(object):
 
     def append(self, item):
         if not isinstance(item, TestCase):
-            raise TypeError('only TestCase instances may be appended to a TestSuite instance')
+            raise TypeError(
+                'only TestCase instances may be appended to TestSuite')
         self.tests.append(item)  # Append the item to the list of tests
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         # Prepare the header for the entire test suite
-        number_of_errors = sum(x.result_type == TestResult.ERRORED for x in self.tests)
+        number_of_errors = sum(
+            x.result_type == TestResult.ERRORED for x in self.tests)
         self.root.set('errors', str(number_of_errors))
-        number_of_failures = sum(x.result_type == TestResult.FAILED for x in self.tests)
+        number_of_failures = sum(
+            x.result_type == TestResult.FAILED for x in self.tests)
         self.root.set('failures', str(number_of_failures))
         self.root.set('tests', str(len(self.tests)))
 
@@ -112,7 +116,8 @@ class TestCase(object):
             self.element.set('time', str(time))
         self.result_type = None
 
-    def set_result(self, result_type, message=None, error_type=None, text=None):
+    def set_result(self, result_type,
+                   message=None, error_type=None, text=None):
         self.result_type = result_type
         result = TestCase.results[self.result_type]
         if result is not None and result is not TestResult.PASSED:
@@ -155,13 +160,19 @@ def install_single_spec(spec, number_of_jobs):
     # If it is already installed, skip the test
     if spack.repo.get(spec).installed:
         testcase = TestCase(package.name, package.spec.short_spec, time=0.0)
-        testcase.set_result(TestResult.SKIPPED, message='Skipped [already installed]', error_type='already_installed')
+        testcase.set_result(
+            TestResult.SKIPPED,
+            message='Skipped [already installed]',
+            error_type='already_installed')
         return testcase
 
     # If it relies on dependencies that did not install, skip
     if failed_dependencies(spec):
         testcase = TestCase(package.name, package.spec.short_spec, time=0.0)
-        testcase.set_result(TestResult.SKIPPED, message='Skipped [failed dependencies]', error_type='dep_failed')
+        testcase.set_result(
+            TestResult.SKIPPED,
+            message='Skipped [failed dependencies]',
+            error_type='dep_failed')
         return testcase
 
     # Otherwise try to install the spec
@@ -177,26 +188,30 @@ def install_single_spec(spec, number_of_jobs):
         testcase = TestCase(package.name, package.spec.short_spec, duration)
         testcase.set_result(TestResult.PASSED)
     except InstallError:
-        # An InstallError is considered a failure (the recipe didn't work correctly)
+        # An InstallError is considered a failure (the recipe didn't work
+        # correctly)
         duration = time.time() - start_time
         # Try to get the log
         lines = fetch_log(package.build_log_path)
         text = '\n'.join(lines)
         testcase = TestCase(package.name, package.spec.short_spec, duration)
-        testcase.set_result(TestResult.FAILED, message='Installation failure', text=text)
+        testcase.set_result(TestResult.FAILED,
+                            message='Installation failure', text=text)
 
     except FetchError:
         # A FetchError is considered an error (we didn't even start building)
         duration = time.time() - start_time
         testcase = TestCase(package.name, package.spec.short_spec, duration)
-        testcase.set_result(TestResult.ERRORED, message='Unable to fetch package')
+        testcase.set_result(TestResult.ERRORED,
+                            message='Unable to fetch package')
 
     return testcase
 
 
 def get_filename(args, top_spec):
     if not args.output:
-        fname = 'test-{x.name}-{x.version}-{hash}.xml'.format(x=top_spec, hash=top_spec.dag_hash())
+        fname = 'test-{x.name}-{x.version}-{hash}.xml'.format(
+            x=top_spec, hash=top_spec.dag_hash())
         output_directory = join_path(os.getcwd(), 'test-output')
         if not os.path.exists(output_directory):
             os.mkdir(output_directory)
diff --git a/lib/spack/spack/cmd/test.py b/lib/spack/spack/cmd/test.py
index b9f2a449ae..bf7342f606 100644
--- a/lib/spack/spack/cmd/test.py
+++ b/lib/spack/spack/cmd/test.py
@@ -52,6 +52,7 @@ def setup_parser(subparser):
 
 
 class MockCache(object):
+
     def store(self, copyCmd, relativeDst):
         pass
 
@@ -60,6 +61,7 @@ class MockCache(object):
 
 
 class MockCacheFetcher(object):
+
     def set_stage(self, stage):
         pass
 
diff --git a/lib/spack/spack/cmd/uninstall.py b/lib/spack/spack/cmd/uninstall.py
index dbe6cd6584..8957d1c908 100644
--- a/lib/spack/spack/cmd/uninstall.py
+++ b/lib/spack/spack/cmd/uninstall.py
@@ -50,25 +50,27 @@ def setup_parser(subparser):
     subparser.add_argument(
         '-f', '--force', action='store_true', dest='force',
         help="Remove regardless of whether other packages depend on this one.")
+
     subparser.add_argument(
         '-a', '--all', action='store_true', dest='all',
-        help="USE CAREFULLY. Remove ALL installed packages that match each " +
-             "supplied spec. i.e., if you say uninstall libelf, ALL versions of " +  # NOQA: ignore=E501
-             "libelf are uninstalled. This is both useful and dangerous, like rm -r.")  # NOQA: ignore=E501
+        help="USE CAREFULLY. Remove ALL installed packages that match each "
+             "supplied spec. i.e., if you say uninstall libelf, ALL versions "
+             "of libelf are uninstalled. This is both useful and dangerous, "
+             "like rm -r.")
+
     subparser.add_argument(
         '-d', '--dependents', action='store_true', dest='dependents',
-        help='Also uninstall any packages that depend on the ones given via command line.'  # NOQA: ignore=E501
-    )
+        help='Also uninstall any packages that depend on the ones given '
+             'via command line.')
+
     subparser.add_argument(
         '-y', '--yes-to-all', action='store_true', dest='yes_to_all',
-        help='Assume "yes" is the answer to every confirmation asked to the user.'  # NOQA: ignore=E501
+        help='Assume "yes" is the answer to every confirmation requested')
 
-    )
     subparser.add_argument(
         'packages',
         nargs=argparse.REMAINDER,
-        help="specs of packages to uninstall"
-    )
+        help="specs of packages to uninstall")
 
 
 def concretize_specs(specs, allow_multiple_matches=False, force=False):
diff --git a/lib/spack/spack/cmd/unload.py b/lib/spack/spack/cmd/unload.py
index 7bd15750ed..b52bedb7b4 100644
--- a/lib/spack/spack/cmd/unload.py
+++ b/lib/spack/spack/cmd/unload.py
@@ -25,13 +25,15 @@
 import argparse
 import spack.modules
 
-description ="Remove package from environment using module."
+description = "Remove package from environment using module."
+
 
 def setup_parser(subparser):
     """Parser is only constructed so that this prints a nice help
        message with -h. """
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help='Spec of package to unload with modules.')
+        'spec', nargs=argparse.REMAINDER,
+        help='Spec of package to unload with modules.')
 
 
 def unload(parser, args):
diff --git a/lib/spack/spack/cmd/unuse.py b/lib/spack/spack/cmd/unuse.py
index 789a690e9c..6403cf6162 100644
--- a/lib/spack/spack/cmd/unuse.py
+++ b/lib/spack/spack/cmd/unuse.py
@@ -25,13 +25,15 @@
 import argparse
 import spack.modules
 
-description ="Remove package from environment using dotkit."
+description = "Remove package from environment using dotkit."
+
 
 def setup_parser(subparser):
     """Parser is only constructed so that this prints a nice help
        message with -h. """
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help='Spec of package to unuse with dotkit.')
+        'spec', nargs=argparse.REMAINDER,
+        help='Spec of package to unuse with dotkit.')
 
 
 def unuse(parser, args):
diff --git a/lib/spack/spack/cmd/url-parse.py b/lib/spack/spack/cmd/url-parse.py
index ce12a17d13..b8c7c95040 100644
--- a/lib/spack/spack/cmd/url-parse.py
+++ b/lib/spack/spack/cmd/url-parse.py
@@ -22,28 +22,28 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import sys
-
 import llnl.util.tty as tty
 
 import spack
 import spack.url
 from spack.util.web import find_versions_of_archive
 
-description = "Show parsing of a URL, optionally spider web for other versions."
+description = "Show parsing of a URL, optionally spider web for versions."
+
 
 def setup_parser(subparser):
     subparser.add_argument('url', help="url of a package archive")
     subparser.add_argument(
-        '-s', '--spider', action='store_true', help="Spider the source page for versions.")
+        '-s', '--spider', action='store_true',
+        help="Spider the source page for versions.")
 
 
 def print_name_and_version(url):
     name, ns, nl, ntup, ver, vs, vl, vtup = spack.url.substitution_offsets(url)
-    underlines = [" "] * max(ns+nl, vs+vl)
-    for i in range(ns, ns+nl):
+    underlines = [" "] * max(ns + nl, vs + vl)
+    for i in range(ns, ns + nl):
         underlines[i] = '-'
-    for i in range(vs, vs+vl):
+    for i in range(vs, vs + vl):
         underlines[i] = '~'
 
     print "    %s" % url
diff --git a/lib/spack/spack/cmd/urls.py b/lib/spack/spack/cmd/urls.py
index 2fe2019a22..f151581d7d 100644
--- a/lib/spack/spack/cmd/urls.py
+++ b/lib/spack/spack/cmd/urls.py
@@ -22,12 +22,12 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import sys
 import spack
 import spack.url
 
 description = "Inspect urls used by packages in spack."
 
+
 def setup_parser(subparser):
     subparser.add_argument(
         '-c', '--color', action='store_true',
@@ -53,6 +53,7 @@ def urls(parser, args):
 
     for url in sorted(urls):
         if args.color or args.extrapolation:
-            print spack.url.color_url(url, subs=args.extrapolation, errors=True)
+            print spack.url.color_url(
+                url, subs=args.extrapolation, errors=True)
         else:
             print url
diff --git a/lib/spack/spack/cmd/use.py b/lib/spack/spack/cmd/use.py
index bbb90fde1b..e3612ace48 100644
--- a/lib/spack/spack/cmd/use.py
+++ b/lib/spack/spack/cmd/use.py
@@ -25,13 +25,15 @@
 import argparse
 import spack.modules
 
-description ="Add package to environment using dotkit."
+description = "Add package to environment using dotkit."
+
 
 def setup_parser(subparser):
     """Parser is only constructed so that this prints a nice help
        message with -h. """
     subparser.add_argument(
-        'spec', nargs=argparse.REMAINDER, help='Spec of package to use with dotkit.')
+        'spec', nargs=argparse.REMAINDER,
+        help='Spec of package to use with dotkit.')
 
 
 def use(parser, args):
diff --git a/lib/spack/spack/cmd/versions.py b/lib/spack/spack/cmd/versions.py
index ec3a4b2e34..1e95225ab8 100644
--- a/lib/spack/spack/cmd/versions.py
+++ b/lib/spack/spack/cmd/versions.py
@@ -22,15 +22,16 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import os
 from llnl.util.tty.colify import colify
 import llnl.util.tty as tty
 import spack
 
-description ="List available versions of a package"
+description = "List available versions of a package"
+
 
 def setup_parser(subparser):
-    subparser.add_argument('package', metavar='PACKAGE', help='Package to list versions for')
+    subparser.add_argument('package', metavar='PACKAGE',
+                           help='Package to list versions for')
 
 
 def versions(parser, args):
diff --git a/lib/spack/spack/compiler.py b/lib/spack/spack/compiler.py
index ce4555bc56..a77991e4dc 100644
--- a/lib/spack/spack/compiler.py
+++ b/lib/spack/spack/compiler.py
@@ -25,10 +25,8 @@
 import os
 import re
 import itertools
-from datetime import datetime
 
 import llnl.util.tty as tty
-from llnl.util.lang import memoized
 from llnl.util.filesystem import join_path
 
 import spack.error
@@ -37,10 +35,10 @@ import spack.architecture
 from spack.util.multiproc import parmap
 from spack.util.executable import *
 from spack.util.environment import get_path
-from spack.version import Version
 
 __all__ = ['Compiler', 'get_compiler_version']
 
+
 def _verify_executables(*paths):
     for path in paths:
         if not os.path.isfile(path) and os.access(path, os.X_OK):
@@ -49,8 +47,9 @@ def _verify_executables(*paths):
 
 _version_cache = {}
 
+
 def get_compiler_version(compiler_path, version_arg, regex='(.*)'):
-    if not compiler_path in _version_cache:
+    if compiler_path not in _version_cache:
         compiler = Executable(compiler_path)
         output = compiler(version_arg, output=str, error=str)
 
@@ -113,7 +112,7 @@ class Compiler(object):
     # Name of module used to switch versions of this compiler
     PrgEnv_compiler = None
 
-    def __init__(self, cspec, operating_system, 
+    def __init__(self, cspec, operating_system,
                  paths, modules=[], alias=None, **kwargs):
         def check(exe):
             if exe is None:
@@ -130,11 +129,6 @@ class Compiler(object):
             else:
                 self.fc  = check(paths[3])
 
-        #self.cc  = check(cc)
-        #self.cxx = check(cxx)
-        #self.f77 = check(f77)
-        #self.fc  = check(fc)
-
         # Unfortunately have to make sure these params are accepted
         # in the same order they are returned by sorted(flags)
         # in compilers/__init__.py
@@ -158,31 +152,30 @@ class Compiler(object):
     @property
     def openmp_flag(self):
         # If it is not overridden, assume it is not supported and warn the user
-        tty.die("The compiler you have chosen does not currently support OpenMP.",
-                "If you think it should, please edit the compiler subclass and",
-                "submit a pull request or issue.")
-
+        tty.die(
+            "The compiler you have chosen does not currently support OpenMP.",
+            "If you think it should, please edit the compiler subclass and",
+            "submit a pull request or issue.")
 
     # This property should be overridden in the compiler subclass if
     # C++11 is supported by that compiler
     @property
     def cxx11_flag(self):
         # If it is not overridden, assume it is not supported and warn the user
-        tty.die("The compiler you have chosen does not currently support C++11.",
-                "If you think it should, please edit the compiler subclass and",
-                "submit a pull request or issue.")
-
+        tty.die(
+            "The compiler you have chosen does not currently support C++11.",
+            "If you think it should, please edit the compiler subclass and",
+            "submit a pull request or issue.")
 
     # This property should be overridden in the compiler subclass if
     # C++14 is supported by that compiler
     @property
     def cxx14_flag(self):
         # If it is not overridden, assume it is not supported and warn the user
-        tty.die("The compiler you have chosen does not currently support C++14.",
-                "If you think it should, please edit the compiler subclass and",
-                "submit a pull request or issue.")
-
-
+        tty.die(
+            "The compiler you have chosen does not currently support C++14.",
+            "If you think it should, please edit the compiler subclass and",
+            "submit a pull request or issue.")
 
     #
     # Compiler classes have methods for querying the version of
@@ -191,7 +184,6 @@ class Compiler(object):
     # Compiler *instances* are just data objects, and can only be
     # constructed from an actual set of executables.
     #
-
     @classmethod
     def default_version(cls, cc):
         """Override just this to override all compiler version functions."""
@@ -258,16 +250,19 @@ class Compiler(object):
                 version = detect_version(full_path)
                 return (version, prefix, suffix, full_path)
             except ProcessError, e:
-                tty.debug("Couldn't get version for compiler %s" % full_path, e)
+                tty.debug(
+                    "Couldn't get version for compiler %s" % full_path, e)
                 return None
             except Exception, e:
                 # Catching "Exception" here is fine because it just
                 # means something went wrong running a candidate executable.
-                tty.debug("Error while executing candidate compiler %s" % full_path,
-                          "%s: %s" %(e.__class__.__name__, e))
+                tty.debug("Error while executing candidate compiler %s"
+                          % full_path,
+                          "%s: %s" % (e.__class__.__name__, e))
                 return None
 
-        successful = [key for key in parmap(check, checks) if key is not None]
+        successful = [k for k in parmap(check, checks) if k is not None]
+
         # The 'successful' list is ordered like the input paths.
         # Reverse it here so that the dict creation (last insert wins)
         # does not spoil the intented precedence.
@@ -278,20 +273,23 @@ class Compiler(object):
         """Return a string representation of the compiler toolchain."""
         return self.__str__()
 
-
     def __str__(self):
         """Return a string representation of the compiler toolchain."""
         return "%s(%s)" % (
-            self.name, '\n     '.join((str(s) for s in (self.cc, self.cxx, self.f77, self.fc, self.modules, str(self.operating_system)))))
+            self.name, '\n     '.join((str(s) for s in (
+                self.cc, self.cxx, self.f77, self.fc, self.modules,
+                str(self.operating_system)))))
 
 
 class CompilerAccessError(spack.error.SpackError):
+
     def __init__(self, path):
         super(CompilerAccessError, self).__init__(
             "'%s' is not a valid compiler." % path)
 
 
 class InvalidCompilerError(spack.error.SpackError):
+
     def __init__(self):
         super(InvalidCompilerError, self).__init__(
             "Compiler has no executables.")
diff --git a/lib/spack/spack/compilers/__init__.py b/lib/spack/spack/compilers/__init__.py
index 0ba94741da..eb866c8bbb 100644
--- a/lib/spack/spack/compilers/__init__.py
+++ b/lib/spack/spack/compilers/__init__.py
@@ -26,15 +26,9 @@
 system and configuring Spack to use multiple compilers.
 """
 import imp
-import os
 import platform
-import copy
-import hashlib
-import base64
-import yaml
-import sys
 
-from llnl.util.lang import memoized, list_modules
+from llnl.util.lang import list_modules
 from llnl.util.filesystem import join_path
 
 import spack
@@ -43,11 +37,7 @@ import spack.spec
 import spack.config
 import spack.architecture
 
-from spack.util.multiproc import parmap
-from spack.compiler import Compiler
-from spack.util.executable import which
 from spack.util.naming import mod_to_class
-from spack.util.environment import get_path
 
 _imported_compilers_module = 'spack.compilers'
 _path_instance_vars = ['cc', 'cxx', 'f77', 'fc']
@@ -73,7 +63,8 @@ def _to_dict(compiler):
     """Return a dict version of compiler suitable to insert in YAML."""
     d = {}
     d['spec'] = str(compiler.spec)
-    d['paths'] = dict( (attr, getattr(compiler, attr, None)) for attr in _path_instance_vars )
+    d['paths'] = dict((attr, getattr(compiler, attr, None))
+                      for attr in _path_instance_vars)
     d['operating_system'] = str(compiler.operating_system)
     d['modules'] = compiler.modules if compiler.modules else []
 
@@ -140,15 +131,19 @@ def remove_compiler_from_config(compiler_spec, scope=None):
       - compiler_specs: a list of CompilerSpec objects.
       - scope:          configuration scope to modify.
     """
+    # Need a better way for this
+    global _cache_config_file
+
     compiler_config = get_compiler_config(scope)
     config_length = len(compiler_config)
 
-    filtered_compiler_config = [comp for comp in compiler_config
-               if spack.spec.CompilerSpec(comp['compiler']['spec']) != compiler_spec]
-    # Need a better way for this
-    global _cache_config_file
-    _cache_config_file = filtered_compiler_config # Update the cache for changes
-    if len(filtered_compiler_config) == config_length: # No items removed
+    filtered_compiler_config = [
+        comp for comp in compiler_config
+        if spack.spec.CompilerSpec(comp['compiler']['spec']) != compiler_spec]
+
+    # Update the cache for changes
+    _cache_config_file = filtered_compiler_config
+    if len(filtered_compiler_config) == config_length:  # No items removed
         CompilerSpecInsufficientlySpecificError(compiler_spec)
     spack.config.update_config('compilers', filtered_compiler_config, scope)
 
@@ -158,7 +153,8 @@ def all_compilers_config(scope=None, init_config=True):
        available to build with.  These are instances of CompilerSpec.
     """
     # Get compilers for this architecture.
-    global _cache_config_file #Create a cache of the config file so we don't load all the time.
+    # Create a cache of the config file so we don't load all the time.
+    global _cache_config_file
     if not _cache_config_file:
         _cache_config_file = get_compiler_config(scope, init_config)
         return _cache_config_file
@@ -236,7 +232,8 @@ def compilers_for_spec(compiler_spec, scope=None, **kwargs):
                 continue
             items = items['compiler']
 
-            if not ('paths' in items and all(n in items['paths'] for n in _path_instance_vars)):
+            if not ('paths' in items and
+                    all(n in items['paths'] for n in _path_instance_vars)):
                 raise InvalidCompilerConfigurationError(cspec)
 
             cls  = class_for_compiler_name(cspec.name)
@@ -254,10 +251,10 @@ def compilers_for_spec(compiler_spec, scope=None, **kwargs):
                 mods = []
 
             if 'operating_system' in items:
-                operating_system = spack.architecture._operating_system_from_dict(items['operating_system'], platform)
+                os = spack.architecture._operating_system_from_dict(
+                    items['operating_system'], platform)
             else:
-                operating_system = None
-
+                os = None
 
             alias = items['alias'] if 'alias' in items else None
 
@@ -266,7 +263,8 @@ def compilers_for_spec(compiler_spec, scope=None, **kwargs):
                 if f in items:
                     flags[f] = items[f]
 
-            compilers.append(cls(cspec, operating_system, compiler_paths, mods, alias, **flags))
+            compilers.append(
+                cls(cspec, os, compiler_paths, mods, alias, **flags))
 
         return compilers
 
@@ -275,7 +273,6 @@ def compilers_for_spec(compiler_spec, scope=None, **kwargs):
     for cspec in matches:
         compilers.extend(get_compilers(cspec))
     return compilers
-#    return [get_compilers(cspec) for cspec in matches]
 
 
 @_auto_compiler_spec
@@ -285,8 +282,9 @@ def compiler_for_spec(compiler_spec, arch):
     operating_system = arch.platform_os
     assert(compiler_spec.concrete)
 
-    compilers = [c for c in compilers_for_spec(compiler_spec, platform=arch.platform)
-                if c.operating_system == operating_system]
+    compilers = [
+        c for c in compilers_for_spec(compiler_spec, platform=arch.platform)
+        if c.operating_system == operating_system]
     if len(compilers) < 1:
         raise NoCompilerForSpecError(compiler_spec, operating_system)
     if len(compilers) > 1:
@@ -321,11 +319,13 @@ def all_os_classes():
 
     return classes
 
+
 def all_compiler_types():
     return [class_for_compiler_name(c) for c in supported_compilers()]
 
 
 class InvalidCompilerConfigurationError(spack.error.SpackError):
+
     def __init__(self, compiler_spec):
         super(InvalidCompilerConfigurationError, self).__init__(
             "Invalid configuration for [compiler \"%s\"]: " % compiler_spec,
@@ -335,14 +335,18 @@ class InvalidCompilerConfigurationError(spack.error.SpackError):
 
 class NoCompilersError(spack.error.SpackError):
     def __init__(self):
-        super(NoCompilersError, self).__init__("Spack could not find any compilers!")
+        super(NoCompilersError, self).__init__(
+            "Spack could not find any compilers!")
+
 
 class NoCompilerForSpecError(spack.error.SpackError):
     def __init__(self, compiler_spec, target):
-        super(NoCompilerForSpecError, self).__init__("No compilers for operating system %s satisfy spec %s" % (
-                                                     target, compiler_spec))
+        super(NoCompilerForSpecError, self).__init__(
+            "No compilers for operating system %s satisfy spec %s"
+            % (target, compiler_spec))
+
 
 class CompilerSpecInsufficientlySpecificError(spack.error.SpackError):
     def __init__(self, compiler_spec):
-        super(CompilerSpecInsufficientlySpecificError, self).__init__("Multiple compilers satisfy spec %s",
-                                                                      compiler_spec)
+        super(CompilerSpecInsufficientlySpecificError, self).__init__(
+            "Multiple compilers satisfy spec %s" % compiler_spec)
diff --git a/lib/spack/spack/compilers/clang.py b/lib/spack/spack/compilers/clang.py
index 00b406d820..4cf65222ae 100644
--- a/lib/spack/spack/compilers/clang.py
+++ b/lib/spack/spack/compilers/clang.py
@@ -29,6 +29,7 @@ from spack.util.executable import *
 import llnl.util.tty as tty
 from spack.version import ver
 
+
 class Clang(Compiler):
     # Subclasses use possible names of C compiler
     cc_names = ['clang']
@@ -43,11 +44,12 @@ class Clang(Compiler):
     fc_names = []
 
     # Named wrapper links within spack.build_env_path
-    link_paths = { 'cc'  : 'clang/clang',
-                   'cxx' : 'clang/clang++',
-                   # Use default wrappers for fortran, in case provided in compilers.yaml
-                   'f77' : 'f77',
-                   'fc'  : 'f90' }
+    link_paths = {'cc': 'clang/clang',
+                  'cxx': 'clang/clang++',
+                  # Use default wrappers for fortran, in case provided in
+                  # compilers.yaml
+                  'f77': 'f77',
+                  'fc': 'f90'}
 
     @property
     def is_apple(self):
diff --git a/lib/spack/spack/compilers/craype.py b/lib/spack/spack/compilers/craype.py
index 4ba8b110ec..c92e5c131a 100644
--- a/lib/spack/spack/compilers/craype.py
+++ b/lib/spack/spack/compilers/craype.py
@@ -1,34 +1,33 @@
-##############################################################################}
-# Copyright (c) 2013, Lawrence Livermore National Security, LLC.
+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
 # Produced at the Lawrence Livermore National Laboratory.
 #
 # This file is part of Spack.
-# Written by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
 # LLNL-CODE-647188
 #
-# For details, see https://scalability-llnl.github.io/spack
+# For details, see https://github.com/llnl/spack
 # Please also see the LICENSE file for our notice and the LGPL.
 #
 # This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License (as published by
-# the Free Software Foundation) version 2.1 dated February 1999.
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
 #
 # This program is distributed in the hope that it will be useful, but
 # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
-# conditions of the GNU General Public License for more details.
+# conditions of the GNU Lesser General Public License for more details.
 #
-# You should have received a copy of the GNU Lesser General Public License
-# along with this program; if not, write to the Free Software Foundation,
-# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import llnl.util.tty as tty
-
-#from spack.build_environment import load_module
 from spack.compiler import *
-#from spack.version import ver
+
 
 class Craype(Compiler):
+    """Cray programming environment compiler."""
+
     # Subclasses use possible names of C compiler
     cc_names = ['cc']
 
@@ -47,12 +46,11 @@ class Craype(Compiler):
     PrgEnv = 'PrgEnv-cray'
     PrgEnv_compiler = 'craype'
 
-    link_paths = { 'cc'  : 'cc',
-                   'cxx' : 'c++',
-                   'f77' : 'f77',
-                   'fc'  : 'fc'}
- 
+    link_paths = {'cc': 'cc',
+                  'cxx': 'c++',
+                  'f77': 'f77',
+                  'fc': 'fc'}
+
     @classmethod
     def default_version(cls, comp):
         return get_compiler_version(comp, r'([Vv]ersion).*(\d+(\.\d+)+)')
-
diff --git a/lib/spack/spack/compilers/gcc.py b/lib/spack/spack/compilers/gcc.py
index 2fae6688db..a556f346d7 100644
--- a/lib/spack/spack/compilers/gcc.py
+++ b/lib/spack/spack/compilers/gcc.py
@@ -26,6 +26,7 @@ import llnl.util.tty as tty
 from spack.compiler import *
 from spack.version import ver
 
+
 class Gcc(Compiler):
     # Subclasses use possible names of C compiler
     cc_names = ['gcc']
@@ -44,10 +45,10 @@ class Gcc(Compiler):
     suffixes = [r'-mp-\d\.\d', r'-\d\.\d', r'-\d']
 
     # Named wrapper links within spack.build_env_path
-    link_paths = {'cc'  : 'gcc/gcc',
-                  'cxx' : 'gcc/g++',
-                  'f77' : 'gcc/gfortran',
-                  'fc'  : 'gcc/gfortran' }
+    link_paths = {'cc': 'gcc/gcc',
+                  'cxx': 'gcc/g++',
+                  'f77': 'gcc/gfortran',
+                  'fc': 'gcc/gfortran'}
 
     PrgEnv = 'PrgEnv-gnu'
     PrgEnv_compiler = 'gcc'
@@ -79,7 +80,6 @@ class Gcc(Compiler):
             # older gfortran versions don't have simple dumpversion output.
             r'(?:GNU Fortran \(GCC\))?(\d+\.\d+(?:\.\d+)?)')
 
-
     @classmethod
     def f77_version(cls, f77):
         return cls.fc_version(f77)
diff --git a/lib/spack/spack/compilers/intel.py b/lib/spack/spack/compilers/intel.py
index 6cad03ff47..8531ecd19a 100644
--- a/lib/spack/spack/compilers/intel.py
+++ b/lib/spack/spack/compilers/intel.py
@@ -26,6 +26,7 @@ from spack.compiler import *
 import llnl.util.tty as tty
 from spack.version import ver
 
+
 class Intel(Compiler):
     # Subclasses use possible names of C compiler
     cc_names = ['icc']
@@ -40,10 +41,10 @@ class Intel(Compiler):
     fc_names = ['ifort']
 
     # Named wrapper links within spack.build_env_path
-    link_paths = { 'cc'  : 'intel/icc',
-                   'cxx' : 'intel/icpc',
-                   'f77' : 'intel/ifort',
-                   'fc'  : 'intel/ifort' }
+    link_paths = {'cc': 'intel/icc',
+                  'cxx': 'intel/icpc',
+                  'f77': 'intel/ifort',
+                  'fc': 'intel/ifort'}
 
     PrgEnv = 'PrgEnv-intel'
     PrgEnv_compiler = 'intel'
@@ -64,7 +65,6 @@ class Intel(Compiler):
         else:
             return "-std=c++11"
 
-
     @classmethod
     def default_version(cls, comp):
         """The '--version' option seems to be the most consistent one
diff --git a/lib/spack/spack/compilers/nag.py b/lib/spack/spack/compilers/nag.py
index cee11bc97a..fdfc078b5e 100644
--- a/lib/spack/spack/compilers/nag.py
+++ b/lib/spack/spack/compilers/nag.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 from spack.compiler import *
-import llnl.util.tty as tty
+
 
 class Nag(Compiler):
     # Subclasses use possible names of C compiler
@@ -39,11 +39,12 @@ class Nag(Compiler):
     fc_names = ['nagfor']
 
     # Named wrapper links within spack.build_env_path
-    link_paths = { # Use default wrappers for C and C++, in case provided in compilers.yaml
-                   'cc'  : 'cc',
-                   'cxx' : 'c++',
-                   'f77' : 'nag/nagfor',
-                   'fc'  : 'nag/nagfor' }
+    # Use default wrappers for C and C++, in case provided in compilers.yaml
+    link_paths = {
+        'cc': 'cc',
+        'cxx': 'c++',
+        'f77': 'nag/nagfor',
+        'fc': 'nag/nagfor'}
 
     @property
     def openmp_flag(self):
@@ -71,9 +72,8 @@ class Nag(Compiler):
         """The '-V' option works for nag compilers.
            Output looks like this::
 
-               NAG Fortran Compiler Release 6.0(Hibiya) Build 1037
-               Product NPL6A60NA for x86-64 Linux
-               Copyright 1990-2015 The Numerical Algorithms Group Ltd., Oxford, U.K.
+           NAG Fortran Compiler Release 6.0(Hibiya) Build 1037
+           Product NPL6A60NA for x86-64 Linux
         """
         return get_compiler_version(
             comp, '-V', r'NAG Fortran Compiler Release ([0-9.]+)')
diff --git a/lib/spack/spack/compilers/pgi.py b/lib/spack/spack/compilers/pgi.py
index 6d36d8bfa6..0e4be6e9ba 100644
--- a/lib/spack/spack/compilers/pgi.py
+++ b/lib/spack/spack/compilers/pgi.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 from spack.compiler import *
-import llnl.util.tty as tty
+
 
 class Pgi(Compiler):
     # Subclasses use possible names of C compiler
@@ -39,17 +39,14 @@ class Pgi(Compiler):
     fc_names = ['pgfortran', 'pgf95', 'pgf90']
 
     # Named wrapper links within spack.build_env_path
-    link_paths = { 'cc'  : 'pgi/pgcc',
-                   'cxx' : 'pgi/pgc++',
-                   'f77' : 'pgi/pgfortran',
-                   'fc'  : 'pgi/pgfortran' }
-
-
+    link_paths = {'cc': 'pgi/pgcc',
+                  'cxx': 'pgi/pgc++',
+                  'f77': 'pgi/pgfortran',
+                  'fc': 'pgi/pgfortran'}
 
     PrgEnv = 'PrgEnv-pgi'
     PrgEnv_compiler = 'pgi'
 
-
     @property
     def openmp_flag(self):
         return "-mp"
diff --git a/lib/spack/spack/compilers/xl.py b/lib/spack/spack/compilers/xl.py
index b1431436ad..5c83209781 100644
--- a/lib/spack/spack/compilers/xl.py
+++ b/lib/spack/spack/compilers/xl.py
@@ -26,24 +26,26 @@ from spack.compiler import *
 import llnl.util.tty as tty
 from spack.version import ver
 
+
 class Xl(Compiler):
     # Subclasses use possible names of C compiler
-    cc_names = ['xlc','xlc_r']
+    cc_names = ['xlc', 'xlc_r']
 
     # Subclasses use possible names of C++ compiler
-    cxx_names = ['xlC','xlC_r','xlc++','xlc++_r']
+    cxx_names = ['xlC', 'xlC_r', 'xlc++', 'xlc++_r']
 
     # Subclasses use possible names of Fortran 77 compiler
-    f77_names = ['xlf','xlf_r']
+    f77_names = ['xlf', 'xlf_r']
 
     # Subclasses use possible names of Fortran 90 compiler
-    fc_names = ['xlf90','xlf90_r','xlf95','xlf95_r','xlf2003','xlf2003_r','xlf2008','xlf2008_r']
+    fc_names = ['xlf90', 'xlf90_r', 'xlf95', 'xlf95_r',
+                'xlf2003', 'xlf2003_r', 'xlf2008', 'xlf2008_r']
 
     # Named wrapper links within spack.build_env_path
-    link_paths = { 'cc'  : 'xl/xlc',
-                   'cxx' : 'xl/xlc++',
-                   'f77' : 'xl/xlf',
-                   'fc'  : 'xl/xlf90' }
+    link_paths = {'cc': 'xl/xlc',
+                  'cxx': 'xl/xlc++',
+                  'f77': 'xl/xlf',
+                  'fc': 'xl/xlf90'}
 
     @property
     def openmp_flag(self):
@@ -56,7 +58,6 @@ class Xl(Compiler):
         else:
             return "-qlanglvl=extended0x"
 
-
     @classmethod
     def default_version(cls, comp):
         """The '-qversion' is the standard option fo XL compilers.
@@ -82,29 +83,28 @@ class Xl(Compiler):
         """
 
         return get_compiler_version(
-            comp, '-qversion',r'([0-9]?[0-9]\.[0-9])')
-
+            comp, '-qversion', r'([0-9]?[0-9]\.[0-9])')
 
     @classmethod
     def fc_version(cls, fc):
-        """The fortran and C/C++ versions of the XL compiler are always two units apart.
-           By this we mean that the fortran release that goes with XL C/C++ 11.1 is 13.1.
-           Having such a difference in version number is confusing spack quite a lot.
-           Most notably if you keep the versions as is the default xl compiler will only
-           have fortran and no C/C++.
-           So we associate the Fortran compiler with the version associated to the C/C++
-           compiler.
-           One last stumble. Version numbers over 10 have at least a .1 those under 10
-           a .0. There is no xlf 9.x or under currently available. BG/P and BG/L can
-           such a compiler mix and possibly older version of AIX and linux on power.
+        """The fortran and C/C++ versions of the XL compiler are always
+           two units apart.  By this we mean that the fortran release that
+           goes with XL C/C++ 11.1 is 13.1.  Having such a difference in
+           version number is confusing spack quite a lot.  Most notably
+           if you keep the versions as is the default xl compiler will
+           only have fortran and no C/C++.  So we associate the Fortran
+           compiler with the version associated to the C/C++ compiler.
+           One last stumble. Version numbers over 10 have at least a .1
+           those under 10 a .0. There is no xlf 9.x or under currently
+           available. BG/P and BG/L can such a compiler mix and possibly
+           older version of AIX and linux on power.
         """
-        fver = get_compiler_version(fc, '-qversion',r'([0-9]?[0-9]\.[0-9])')
+        fver = get_compiler_version(fc, '-qversion', r'([0-9]?[0-9]\.[0-9])')
         cver = float(fver) - 2
-        if cver < 10 :
-          cver = cver - 0.1
+        if cver < 10:
+            cver = cver - 0.1
         return str(cver)
 
-
     @classmethod
     def f77_version(cls, f77):
         return cls.fc_version(f77)
diff --git a/lib/spack/spack/concretize.py b/lib/spack/spack/concretize.py
index 6f11c86ce8..726dee62e3 100644
--- a/lib/spack/spack/concretize.py
+++ b/lib/spack/spack/concretize.py
@@ -61,7 +61,9 @@ class DefaultConcretizer(object):
             if not providers:
                 raise UnsatisfiableProviderSpecError(providers[0], spec)
             spec_w_preferred_providers = find_spec(
-                spec, lambda x: spack.pkgsort.spec_has_preferred_provider(x.name, spec.name))  # NOQA: ignore=E501
+                spec,
+                lambda x: spack.pkgsort.spec_has_preferred_provider(
+                    x.name, spec.name))
             if not spec_w_preferred_providers:
                 spec_w_preferred_providers = spec
             provider_cmp = partial(spack.pkgsort.provider_compare,
@@ -495,7 +497,8 @@ class UnavailableCompilerVersionError(spack.error.SpackError):
 
     def __init__(self, compiler_spec, operating_system):
         super(UnavailableCompilerVersionError, self).__init__(
-            "No available compiler version matches '%s' on operating_system %s" % (compiler_spec, operating_system),  # NOQA: ignore=E501
+            "No available compiler version matches '%s' on operating_system %s"
+            % (compiler_spec, operating_system),
             "Run 'spack compilers' to see available compiler Options.")
 
 
@@ -506,14 +509,15 @@ class NoValidVersionError(spack.error.SpackError):
 
     def __init__(self, spec):
         super(NoValidVersionError, self).__init__(
-            "There are no valid versions for %s that match '%s'" % (spec.name, spec.versions))  # NOQA: ignore=E501
+            "There are no valid versions for %s that match '%s'"
+            % (spec.name, spec.versions))
 
 
 class NoBuildError(spack.error.SpackError):
-
     """Raised when a package is configured with the buildable option False, but
        no satisfactory external versions can be found"""
 
     def __init__(self, spec):
-        super(NoBuildError, self).__init__(
-            "The spec '%s' is configured as not buildable,and no matching external installs were found" % spec.name)  # NOQA: ignore=E501
+        msg = ("The spec '%s' is configured as not buildable, "
+               "and no matching external installs were found")
+        super(NoBuildError, self).__init__(msg % spec.name)
diff --git a/lib/spack/spack/config.py b/lib/spack/spack/config.py
index a4e274893c..a4a4f5411e 100644
--- a/lib/spack/spack/config.py
+++ b/lib/spack/spack/config.py
@@ -158,35 +158,35 @@ section_schemas = {
                                 'required': ['cc', 'cxx', 'f77', 'fc'],
                                 'additionalProperties': False,
                                 'properties': {
-                                    'cc':  { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'cxx': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'f77': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'fc':  { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'cflags': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'cxxflags': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'fflags': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'cppflags': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'ldflags': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]},
-                                    'ldlibs': { 'anyOf': [ {'type' : 'string' },
-                                                        {'type' : 'null' }]}}},
-                            'spec': { 'type': 'string'},
-                            'operating_system': { 'type': 'string'},
-                            'alias': { 'anyOf': [ {'type' : 'string'},
-                                                    {'type' : 'null' }]},
-                            'modules': { 'anyOf': [ {'type' : 'string'},
-                                                    {'type' : 'null' },
-                                                    {'type': 'array'},
-                                                    ]}
-                            },},},},},},
+                                    'cc':  {'anyOf': [{'type': 'string'},
+                                                      {'type': 'null'}]},
+                                    'cxx': {'anyOf': [{'type': 'string'},
+                                                      {'type': 'null'}]},
+                                    'f77': {'anyOf': [{'type': 'string'},
+                                                      {'type': 'null'}]},
+                                    'fc':  {'anyOf': [{'type': 'string'},
+                                                      {'type': 'null'}]},
+                                    'cflags': {'anyOf': [{'type': 'string'},
+                                                         {'type': 'null'}]},
+                                    'cxxflags': {'anyOf': [{'type': 'string'},
+                                                           {'type': 'null'}]},
+                                    'fflags': {'anyOf': [{'type': 'string'},
+                                                         {'type': 'null'}]},
+                                    'cppflags': {'anyOf': [{'type': 'string'},
+                                                           {'type': 'null'}]},
+                                    'ldflags': {'anyOf': [{'type': 'string'},
+                                                          {'type': 'null'}]},
+                                    'ldlibs': {'anyOf': [{'type': 'string'},
+                                                         {'type': 'null'}]}}},
+                            'spec': {'type': 'string'},
+                            'operating_system': {'type': 'string'},
+                            'alias': {'anyOf': [{'type': 'string'},
+                                                {'type': 'null'}]},
+                            'modules': {'anyOf': [{'type': 'string'},
+                                                  {'type': 'null'},
+                                                  {'type': 'array'},
+                                                  ]}
+                        }, }, }, }, }, },
     'mirrors': {
         '$schema': 'http://json-schema.org/schema#',
         'title': 'Spack mirror configuration file schema',
@@ -199,7 +199,7 @@ section_schemas = {
                 'additionalProperties': False,
                 'patternProperties': {
                     r'\w[\w-]*': {
-                        'type': 'string'},},},},},
+                        'type': 'string'}, }, }, }, },
 
     'repos': {
         '$schema': 'http://json-schema.org/schema#',
@@ -211,7 +211,7 @@ section_schemas = {
                 'type': 'array',
                 'default': [],
                 'items': {
-                    'type': 'string'},},},},
+                    'type': 'string'}, }, }, },
     'packages': {
         '$schema': 'http://json-schema.org/schema#',
         'title': 'Spack package configuration file schema',
@@ -223,48 +223,48 @@ section_schemas = {
                 'default': {},
                 'additionalProperties': False,
                 'patternProperties': {
-                    r'\w[\w-]*': { # package name
+                    r'\w[\w-]*': {  # package name
                         'type': 'object',
                         'default': {},
                         'additionalProperties': False,
                         'properties': {
                             'version': {
-                                'type' : 'array',
-                                'default' : [],
-                                'items' : { 'anyOf' : [ { 'type' : 'string' },
-                                                        { 'type' : 'number'}]}}, #version strings
+                                'type': 'array',
+                                'default': [],
+                                'items': {'anyOf': [{'type': 'string'},
+                                                    {'type': 'number'}]}},  # version strings
                             'compiler': {
-                                'type' : 'array',
-                                'default' : [],
-                                'items' : { 'type' : 'string' } }, #compiler specs
+                                'type': 'array',
+                                'default': [],
+                                'items': {'type': 'string'}},  # compiler specs
                             'buildable': {
                                 'type':  'boolean',
                                 'default': True,
-                             },
+                            },
                             'modules': {
-                                'type' : 'object',
-                                'default' : {},
-                             },
+                                'type': 'object',
+                                'default': {},
+                            },
                             'providers': {
                                 'type':  'object',
                                 'default': {},
                                 'additionalProperties': False,
                                 'patternProperties': {
                                     r'\w[\w-]*': {
-                                        'type' : 'array',
-                                        'default' : [],
-                                        'items' : { 'type' : 'string' },},},},
+                                        'type': 'array',
+                                        'default': [],
+                                        'items': {'type': 'string'}, }, }, },
                             'paths': {
-                                'type' : 'object',
-                                'default' : {},
-                             },
+                                'type': 'object',
+                                'default': {},
+                            },
                             'variants': {
-                                'oneOf' : [
-                                    { 'type' : 'string' },
-                                    { 'type' : 'array',
-                                      'items' : { 'type' : 'string' } },
-                                    ], },
-                        },},},},},},
+                                'oneOf': [
+                                    {'type': 'string'},
+                                    {'type': 'array',
+                                     'items': {'type': 'string'}},
+                                ], },
+                        }, }, }, }, }, },
 
     'targets': {
         '$schema': 'http://json-schema.org/schema#',
@@ -277,8 +277,8 @@ section_schemas = {
                 'default': {},
                 'additionalProperties': False,
                 'patternProperties': {
-                    r'\w[\w-]*': { # target name
-                        'type': 'string' ,},},},},},
+                    r'\w[\w-]*': {  # target name
+                        'type': 'string', }, }, }, }, },
     'modules': {
         '$schema': 'http://json-schema.org/schema#',
         'title': 'Spack module file configuration file schema',
@@ -389,13 +389,15 @@ section_schemas = {
                     },
                     'tcl': {
                         'allOf': [
-                            {'$ref': '#/definitions/module_type_configuration'},  # Base configuration
+                            # Base configuration
+                            {'$ref': '#/definitions/module_type_configuration'},
                             {}  # Specific tcl extensions
                         ]
                     },
                     'dotkit': {
                         'allOf': [
-                            {'$ref': '#/definitions/module_type_configuration'},  # Base configuration
+                            # Base configuration
+                            {'$ref': '#/definitions/module_type_configuration'},
                             {}  # Specific dotkit extensions
                         ]
                     },
@@ -428,7 +430,8 @@ def extend_with_default(validator_class):
 
     """
     validate_properties = validator_class.VALIDATORS["properties"]
-    validate_pattern_properties = validator_class.VALIDATORS["patternProperties"]
+    validate_pattern_properties = validator_class.VALIDATORS[
+        "patternProperties"]
 
     def set_defaults(validator, properties, instance, schema):
         for property, subschema in properties.iteritems():
@@ -510,7 +513,8 @@ class ConfigScope(object):
         except jsonschema.ValidationError as e:
             raise ConfigSanityError(e, data)
         except (yaml.YAMLError, IOError) as e:
-            raise ConfigFileError("Error writing to config file: '%s'" % str(e))
+            raise ConfigFileError(
+                "Error writing to config file: '%s'" % str(e))
 
     def clear(self):
         """Empty cached config information."""
@@ -739,7 +743,8 @@ def spec_externals(spec):
 
         path = get_path_from_module(module)
 
-        external_spec = spack.spec.Spec(external_spec, external=path, external_module=module)
+        external_spec = spack.spec.Spec(
+            external_spec, external=path, external_module=module)
         if external_spec.satisfies(spec):
             external_specs.append(external_spec)
 
@@ -773,6 +778,7 @@ def get_path(path, data):
 
 class ConfigFormatError(ConfigError):
     """Raised when a configuration format does not match its schema."""
+
     def __init__(self, validation_error, data):
         # Try to get line number from erroneous instance and its parent
         instance_mark = getattr(validation_error.instance, '_start_mark', None)
diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
index 16814429dc..f3dcdef0a9 100644
--- a/lib/spack/spack/database.py
+++ b/lib/spack/spack/database.py
@@ -119,6 +119,7 @@ class InstallRecord(object):
 
 
 class Database(object):
+
     def __init__(self, root, db_dir=None):
         """Create a Database for Spack installations under ``root``.
 
@@ -600,6 +601,7 @@ class Database(object):
 
 
 class CorruptDatabaseError(SpackError):
+
     def __init__(self, path, msg=''):
         super(CorruptDatabaseError, self).__init__(
             "Spack database is corrupt: %s.  %s." % (path, msg),
@@ -607,6 +609,7 @@ class CorruptDatabaseError(SpackError):
 
 
 class InvalidDatabaseVersionError(SpackError):
+
     def __init__(self, expected, found):
         super(InvalidDatabaseVersionError, self).__init__(
             "Expected database version %s but found version %s."
diff --git a/lib/spack/spack/directives.py b/lib/spack/spack/directives.py
index e92dd6fb67..313bf48f0d 100644
--- a/lib/spack/spack/directives.py
+++ b/lib/spack/spack/directives.py
@@ -349,9 +349,10 @@ class CircularReferenceError(DirectiveError):
 
 class UnknownDependencyTypeError(DirectiveError):
     """This is raised when a dependency is of an unknown type."""
+
     def __init__(self, directive, package, deptype):
         super(UnknownDependencyTypeError, self).__init__(
             directive,
-            "Package '%s' cannot depend on a package via %s." %
-                (package, deptype))
+            "Package '%s' cannot depend on a package via %s."
+            % (package, deptype))
         self.package = package
diff --git a/lib/spack/spack/directory_layout.py b/lib/spack/spack/directory_layout.py
index 8150a6da2b..0ae6f765f4 100644
--- a/lib/spack/spack/directory_layout.py
+++ b/lib/spack/spack/directory_layout.py
@@ -22,16 +22,13 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import re
 import os
 import exceptions
-import hashlib
 import shutil
 import glob
 import tempfile
 import yaml
 
-import llnl.util.tty as tty
 from llnl.util.filesystem import join_path, mkdirp
 
 import spack
@@ -51,10 +48,10 @@ class DirectoryLayout(object):
        install, and they can use this to customize the nesting structure of
        spack installs.
     """
+
     def __init__(self, root):
         self.root = root
 
-
     @property
     def hidden_file_paths(self):
         """Return a list of hidden files used by the directory layout.
@@ -67,25 +64,21 @@ class DirectoryLayout(object):
         """
         raise NotImplementedError()
 
-
     def all_specs(self):
         """To be implemented by subclasses to traverse all specs for which there is
            a directory within the root.
         """
         raise NotImplementedError()
 
-
     def relative_path_for_spec(self, spec):
         """Implemented by subclasses to return a relative path from the install
            root to a unique location for the provided spec."""
         raise NotImplementedError()
 
-
     def create_install_directory(self, spec):
         """Creates the installation directory for a spec."""
         raise NotImplementedError()
 
-
     def check_installed(self, spec):
         """Checks whether a spec is installed.
 
@@ -95,7 +88,6 @@ class DirectoryLayout(object):
         """
         raise NotImplementedError()
 
-
     def extension_map(self, spec):
         """Get a dict of currently installed extension packages for a spec.
 
@@ -104,7 +96,6 @@ class DirectoryLayout(object):
         """
         raise NotImplementedError()
 
-
     def check_extension_conflict(self, spec, ext_spec):
         """Ensure that ext_spec can be activated in spec.
 
@@ -113,7 +104,6 @@ class DirectoryLayout(object):
         """
         raise NotImplementedError()
 
-
     def check_activated(self, spec, ext_spec):
         """Ensure that ext_spec can be removed from spec.
 
@@ -121,26 +111,22 @@ class DirectoryLayout(object):
         """
         raise NotImplementedError()
 
-
     def add_extension(self, spec, ext_spec):
         """Add to the list of currently installed extensions."""
         raise NotImplementedError()
 
-
     def remove_extension(self, spec, ext_spec):
         """Remove from the list of currently installed extensions."""
         raise NotImplementedError()
 
-
     def path_for_spec(self, spec):
-        """Return an absolute path from the root to a directory for the spec."""
+        """Return absolute path from the root to a directory for the spec."""
         _check_concrete(spec)
 
         path = self.relative_path_for_spec(spec)
         assert(not path.startswith(self.root))
         return os.path.join(self.root, path)
 
-
     def remove_install_directory(self, spec):
         """Removes a prefix and any empty parent directories from the root.
            Raised RemoveFailedError if something goes wrong.
@@ -177,6 +163,7 @@ class YamlDirectoryLayout(DirectoryLayout):
        only enabled variants are included in the install path.
        Disabled variants are omitted.
     """
+
     def __init__(self, root, **kwargs):
         super(YamlDirectoryLayout, self).__init__(root)
         self.metadata_dir   = kwargs.get('metadata_dir', '.spack')
@@ -191,12 +178,10 @@ class YamlDirectoryLayout(DirectoryLayout):
         # Cache of already written/read extension maps.
         self._extension_maps = {}
 
-
     @property
     def hidden_file_paths(self):
         return (self.metadata_dir,)
 
-
     def relative_path_for_spec(self, spec):
         _check_concrete(spec)
 
@@ -208,20 +193,19 @@ class YamlDirectoryLayout(DirectoryLayout):
             spec.version,
             spec.dag_hash(self.hash_len))
 
-        path = join_path(spec.architecture,
+        path = join_path(
+            spec.architecture,
             "%s-%s" % (spec.compiler.name, spec.compiler.version),
             dir_name)
 
         return path
 
-
     def write_spec(self, spec, path):
         """Write a spec out to a file."""
         _check_concrete(spec)
         with open(path, 'w') as f:
             spec.to_yaml(f)
 
-
     def read_spec(self, path):
         """Read the contents of a file and parse them as a spec"""
         try:
@@ -237,32 +221,26 @@ class YamlDirectoryLayout(DirectoryLayout):
         spec._mark_concrete()
         return spec
 
-
     def spec_file_path(self, spec):
         """Gets full path to spec file"""
         _check_concrete(spec)
         return join_path(self.metadata_path(spec), self.spec_file_name)
 
-
     def metadata_path(self, spec):
         return join_path(self.path_for_spec(spec), self.metadata_dir)
 
-
     def build_log_path(self, spec):
         return join_path(self.path_for_spec(spec), self.metadata_dir,
                          self.build_log_name)
 
-
     def build_env_path(self, spec):
         return join_path(self.path_for_spec(spec), self.metadata_dir,
                          self.build_env_name)
 
-
     def build_packages_path(self, spec):
         return join_path(self.path_for_spec(spec), self.metadata_dir,
                          self.packages_dir)
 
-
     def create_install_directory(self, spec):
         _check_concrete(spec)
 
@@ -273,7 +251,6 @@ class YamlDirectoryLayout(DirectoryLayout):
         mkdirp(self.metadata_path(spec))
         self.write_spec(spec, self.spec_file_path(spec))
 
-
     def check_installed(self, spec):
         _check_concrete(spec)
         path = self.path_for_spec(spec)
@@ -284,7 +261,7 @@ class YamlDirectoryLayout(DirectoryLayout):
 
         if not os.path.isfile(spec_file_path):
             raise InconsistentInstallDirectoryError(
-                'Inconsistent state: install prefix exists but contains no spec.yaml:',
+                'Install prefix exists but contains no spec.yaml:',
                 "  " + path)
 
         installed_spec = self.read_spec(spec_file_path)
@@ -297,7 +274,6 @@ class YamlDirectoryLayout(DirectoryLayout):
             raise InconsistentInstallDirectoryError(
                 'Spec file in %s does not match hash!' % spec_file_path)
 
-
     def all_specs(self):
         if not os.path.isdir(self.root):
             return []
@@ -307,20 +283,17 @@ class YamlDirectoryLayout(DirectoryLayout):
         spec_files = glob.glob(pattern)
         return [self.read_spec(s) for s in spec_files]
 
-
     def specs_by_hash(self):
         by_hash = {}
         for spec in self.all_specs():
             by_hash[spec.dag_hash()] = spec
         return by_hash
 
-
     def extension_file_path(self, spec):
         """Gets full path to an installed package's extension file"""
         _check_concrete(spec)
         return join_path(self.metadata_path(spec), self.extension_file_name)
 
-
     def _write_extensions(self, spec, extensions):
         path = self.extension_file_path(spec)
 
@@ -332,23 +305,22 @@ class YamlDirectoryLayout(DirectoryLayout):
         # write tmp file
         with tmp:
             yaml.dump({
-                'extensions' : [
-                    { ext.name : {
-                        'hash' : ext.dag_hash(),
-                        'path' : str(ext.prefix)
+                'extensions': [
+                    {ext.name: {
+                        'hash': ext.dag_hash(),
+                        'path': str(ext.prefix)
                     }} for ext in sorted(extensions.values())]
             }, tmp, default_flow_style=False)
 
         # Atomic update by moving tmpfile on top of old one.
         os.rename(tmp.name, path)
 
-
     def _extension_map(self, spec):
         """Get a dict<name -> spec> for all extensions currently
            installed for this package."""
         _check_concrete(spec)
 
-        if not spec in self._extension_maps:
+        if spec not in self._extension_maps:
             path = self.extension_file_path(spec)
             if not os.path.exists(path):
                 self._extension_maps[spec] = {}
@@ -363,14 +335,14 @@ class YamlDirectoryLayout(DirectoryLayout):
                         dag_hash = entry[name]['hash']
                         prefix   = entry[name]['path']
 
-                        if not dag_hash in by_hash:
+                        if dag_hash not in by_hash:
                             raise InvalidExtensionSpecError(
                                 "Spec %s not found in %s" % (dag_hash, prefix))
 
                         ext_spec = by_hash[dag_hash]
-                        if not prefix == ext_spec.prefix:
+                        if prefix != ext_spec.prefix:
                             raise InvalidExtensionSpecError(
-                                "Prefix %s does not match spec with hash %s: %s"
+                                "Prefix %s does not match spec hash %s: %s"
                                 % (prefix, dag_hash, ext_spec))
 
                         exts[ext_spec.name] = ext_spec
@@ -378,13 +350,11 @@ class YamlDirectoryLayout(DirectoryLayout):
 
         return self._extension_maps[spec]
 
-
     def extension_map(self, spec):
         """Defensive copying version of _extension_map() for external API."""
         _check_concrete(spec)
         return self._extension_map(spec).copy()
 
-
     def check_extension_conflict(self, spec, ext_spec):
         exts = self._extension_map(spec)
         if ext_spec.name in exts:
@@ -394,13 +364,11 @@ class YamlDirectoryLayout(DirectoryLayout):
             else:
                 raise ExtensionConflictError(spec, ext_spec, installed_spec)
 
-
     def check_activated(self, spec, ext_spec):
         exts = self._extension_map(spec)
-        if (not ext_spec.name in exts) or (ext_spec != exts[ext_spec.name]):
+        if (ext_spec.name not in exts) or (ext_spec != exts[ext_spec.name]):
             raise NoSuchExtensionError(spec, ext_spec)
 
-
     def add_extension(self, spec, ext_spec):
         _check_concrete(spec)
         _check_concrete(ext_spec)
@@ -413,7 +381,6 @@ class YamlDirectoryLayout(DirectoryLayout):
         exts[ext_spec.name] = ext_spec
         self._write_extensions(spec, exts)
 
-
     def remove_extension(self, spec, ext_spec):
         _check_concrete(spec)
         _check_concrete(ext_spec)
@@ -429,12 +396,14 @@ class YamlDirectoryLayout(DirectoryLayout):
 
 class DirectoryLayoutError(SpackError):
     """Superclass for directory layout errors."""
+
     def __init__(self, message, long_msg=None):
         super(DirectoryLayoutError, self).__init__(message, long_msg)
 
 
 class SpecHashCollisionError(DirectoryLayoutError):
     """Raised when there is a hash collision in an install layout."""
+
     def __init__(self, installed_spec, new_spec):
         super(SpecHashCollisionError, self).__init__(
             'Specs %s and %s have the same SHA-1 prefix!'
@@ -443,6 +412,7 @@ class SpecHashCollisionError(DirectoryLayoutError):
 
 class RemoveFailedError(DirectoryLayoutError):
     """Raised when a DirectoryLayout cannot remove an install prefix."""
+
     def __init__(self, installed_spec, prefix, error):
         super(RemoveFailedError, self).__init__(
             'Could not remove prefix %s for %s : %s'
@@ -452,12 +422,15 @@ class RemoveFailedError(DirectoryLayoutError):
 
 class InconsistentInstallDirectoryError(DirectoryLayoutError):
     """Raised when a package seems to be installed to the wrong place."""
+
     def __init__(self, message, long_msg=None):
-        super(InconsistentInstallDirectoryError, self).__init__(message, long_msg)
+        super(InconsistentInstallDirectoryError, self).__init__(
+            message, long_msg)
 
 
 class InstallDirectoryAlreadyExistsError(DirectoryLayoutError):
     """Raised when create_install_directory is called unnecessarily."""
+
     def __init__(self, path):
         super(InstallDirectoryAlreadyExistsError, self).__init__(
             "Install path %s already exists!")
@@ -473,22 +446,26 @@ class InvalidExtensionSpecError(DirectoryLayoutError):
 
 class ExtensionAlreadyInstalledError(DirectoryLayoutError):
     """Raised when an extension is added to a package that already has it."""
+
     def __init__(self, spec, ext_spec):
         super(ExtensionAlreadyInstalledError, self).__init__(
-            "%s is already installed in %s" % (ext_spec.short_spec, spec.short_spec))
+            "%s is already installed in %s"
+            % (ext_spec.short_spec, spec.short_spec))
 
 
 class ExtensionConflictError(DirectoryLayoutError):
     """Raised when an extension is added to a package that already has it."""
+
     def __init__(self, spec, ext_spec, conflict):
         super(ExtensionConflictError, self).__init__(
-            "%s cannot be installed in %s because it conflicts with %s"% (
-                ext_spec.short_spec, spec.short_spec, conflict.short_spec))
+            "%s cannot be installed in %s because it conflicts with %s"
+            % (ext_spec.short_spec, spec.short_spec, conflict.short_spec))
 
 
 class NoSuchExtensionError(DirectoryLayoutError):
     """Raised when an extension isn't there on deactivate."""
+
     def __init__(self, spec, ext_spec):
         super(NoSuchExtensionError, self).__init__(
-            "%s cannot be removed from %s because it's not activated."% (
-                ext_spec.short_spec, spec.short_spec))
+            "%s cannot be removed from %s because it's not activated."
+            % (ext_spec.short_spec, spec.short_spec))
diff --git a/lib/spack/spack/environment.py b/lib/spack/spack/environment.py
index 41136ab2eb..613ece2f45 100644
--- a/lib/spack/spack/environment.py
+++ b/lib/spack/spack/environment.py
@@ -1,4 +1,4 @@
-#
+##############################################################################
 # Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
 # Produced at the Lawrence Livermore National Laboratory.
 #
@@ -21,7 +21,7 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-#
+##############################################################################
 import collections
 import inspect
 import json
@@ -287,7 +287,10 @@ class EnvironmentModifications(object):
         shell = '{shell}'.format(**info)
         shell_options = '{shell_options}'.format(**info)
         source_file = '{source_command} {file} {concatenate_on_success}'
-        dump_environment = 'python -c "import os, json; print json.dumps(dict(os.environ))"'  # NOQA: ignore=E501
+
+        dump_cmd = "import os, json; print json.dumps(dict(os.environ))"
+        dump_environment = 'python -c "%s"' % dump_cmd
+
         # Construct the command that will be executed
         command = [source_file.format(file=file, **info) for file in args]
         command.append(dump_environment)
@@ -326,8 +329,10 @@ class EnvironmentModifications(object):
         for x in unset_variables:
             env.unset(x)
         # Variables that have been modified
-        common_variables = set(this_environment).intersection(set(after_source_env))  # NOQA: ignore=E501
-        modified_variables = [x for x in common_variables if this_environment[x] != after_source_env[x]]  # NOQA: ignore=E501
+        common_variables = set(
+            this_environment).intersection(set(after_source_env))
+        modified_variables = [x for x in common_variables
+                              if this_environment[x] != after_source_env[x]]
 
         def return_separator_if_any(first_value, second_value):
             separators = ':', ';'
@@ -405,7 +410,7 @@ def set_or_unset_not_first(variable, changes, errstream):
     if indexes:
         good = '\t    \t{context} at {filename}:{lineno}'
         nogood = '\t--->\t{context} at {filename}:{lineno}'
-        message = 'Suspicious requests to set or unset the variable \'{var}\' found'  # NOQA: ignore=E501
+        message = "Suspicious requests to set or unset '{var}' found"
         errstream(message.format(var=variable))
         for ii, item in enumerate(changes):
             print_format = nogood if ii in indexes else good
diff --git a/lib/spack/spack/error.py b/lib/spack/spack/error.py
index 85ad2fe249..c94875e91a 100644
--- a/lib/spack/spack/error.py
+++ b/lib/spack/spack/error.py
@@ -27,21 +27,21 @@ import sys
 import llnl.util.tty as tty
 import spack
 
+
 class SpackError(Exception):
     """This is the superclass for all Spack errors.
        Subclasses can be found in the modules they have to do with.
     """
+
     def __init__(self, message, long_message=None):
         super(SpackError, self).__init__()
         self.message = message
         self._long_message = long_message
 
-
     @property
     def long_message(self):
         return self._long_message
 
-
     def die(self):
         if spack.debug:
             sys.excepthook(*sys.exc_info())
@@ -52,21 +52,23 @@ class SpackError(Exception):
                 print self.long_message
             os._exit(1)
 
-
     def __str__(self):
         msg = self.message
         if self._long_message:
             msg += "\n    %s" % self._long_message
         return msg
 
+
 class UnsupportedPlatformError(SpackError):
     """Raised by packages when a platform is not supported"""
+
     def __init__(self, message):
         super(UnsupportedPlatformError, self).__init__(message)
 
 
 class NoNetworkConnectionError(SpackError):
     """Raised when an operation needs an internet connection."""
+
     def __init__(self, message, url):
         super(NoNetworkConnectionError, self).__init__(
             "No network connection: " + str(message),
diff --git a/lib/spack/spack/fetch_strategy.py b/lib/spack/spack/fetch_strategy.py
index bcb33bd0e6..c69a23033c 100644
--- a/lib/spack/spack/fetch_strategy.py
+++ b/lib/spack/spack/fetch_strategy.py
@@ -356,6 +356,7 @@ class URLFetchStrategy(FetchStrategy):
 
 class CacheURLFetchStrategy(URLFetchStrategy):
     """The resource associated with a cache URL may be out of date."""
+
     def __init__(self, *args, **kwargs):
         super(CacheURLFetchStrategy, self).__init__(*args, **kwargs)
 
@@ -836,6 +837,7 @@ def for_package_version(pkg, version):
 
 
 class FsCache(object):
+
     def __init__(self, root):
         self.root = os.path.abspath(root)
 
diff --git a/lib/spack/spack/file_cache.py b/lib/spack/spack/file_cache.py
index fb9ccf46b8..0a66166fd8 100644
--- a/lib/spack/spack/file_cache.py
+++ b/lib/spack/spack/file_cache.py
@@ -41,6 +41,7 @@ class FileCache(object):
       client code need not manage locks for cache entries.
 
     """
+
     def __init__(self, root):
         """Create a file cache object.
 
@@ -131,6 +132,7 @@ class FileCache(object):
 
         """
         class WriteContextManager(object):
+
             def __enter__(cm):
                 cm.orig_filename = self.cache_path(key)
                 cm.orig_file = None
diff --git a/lib/spack/spack/graph.py b/lib/spack/spack/graph.py
index 80d1199ef5..b875e9da99 100644
--- a/lib/spack/spack/graph.py
+++ b/lib/spack/spack/graph.py
@@ -136,6 +136,7 @@ NODE, COLLAPSE, MERGE_RIGHT, EXPAND_RIGHT, BACK_EDGE = states
 
 
 class AsciiGraph(object):
+
     def __init__(self):
         # These can be set after initialization or after a call to
         # graph() to change behavior.
@@ -288,22 +289,22 @@ class AsciiGraph(object):
         self._indent()
 
         for p in prev_ends:
-            advance(p,         lambda: [("| ", self._pos)])  # NOQA: ignore=E272
-            advance(p + 1,     lambda: [("|/", self._pos)])  # NOQA: ignore=E272
+            advance(p,         lambda: [("| ", self._pos)])
+            advance(p + 1,     lambda: [("|/", self._pos)])
 
         if end >= 0:
-            advance(end + 1,   lambda: [("| ", self._pos)])  # NOQA: ignore=E272
-            advance(start - 1, lambda: [("|",  self._pos), ("_", end)])  # NOQA: ignore=E272
+            advance(end + 1,   lambda: [("| ", self._pos)])
+            advance(start - 1, lambda: [("|",  self._pos), ("_", end)])
         else:
-            advance(start - 1, lambda: [("| ", self._pos)])  # NOQA: ignore=E272
+            advance(start - 1, lambda: [("| ", self._pos)])
 
         if start >= 0:
-            advance(start,     lambda: [("|",  self._pos), ("/", end)])  # NOQA: ignore=E272
+            advance(start,     lambda: [("|",  self._pos), ("/", end)])
 
         if collapse:
-            advance(flen,      lambda: [(" /", self._pos)])  # NOQA: ignore=E272
+            advance(flen,      lambda: [(" /", self._pos)])
         else:
-            advance(flen,      lambda: [("| ", self._pos)])  # NOQA: ignore=E272
+            advance(flen,      lambda: [("| ", self._pos)])
 
         self._set_state(BACK_EDGE, end, label)
         self._out.write("\n")
@@ -438,8 +439,8 @@ class AsciiGraph(object):
                     # Expand forward after doing all back connections
 
                     if (i + 1 < len(self._frontier) and
-                       len(self._frontier[i + 1]) == 1 and
-                       self._frontier[i + 1][0] in self._frontier[i]):
+                            len(self._frontier[i + 1]) == 1 and
+                            self._frontier[i + 1][0] in self._frontier[i]):
                         # We need to connect to the element to the right.
                         # Keep lines straight by connecting directly and
                         # avoiding unnecessary expand/contract.
diff --git a/lib/spack/spack/hooks/__init__.py b/lib/spack/spack/hooks/__init__.py
index 902e488eca..c7c84defa0 100644
--- a/lib/spack/spack/hooks/__init__.py
+++ b/lib/spack/spack/hooks/__init__.py
@@ -45,6 +45,7 @@ from llnl.util.lang import memoized, list_modules
 from llnl.util.filesystem import join_path
 import spack
 
+
 @memoized
 def all_hook_modules():
     modules = []
@@ -58,6 +59,7 @@ def all_hook_modules():
 
 
 class HookRunner(object):
+
     def __init__(self, hook_name):
         self.hook_name = hook_name
 
diff --git a/lib/spack/spack/hooks/extensions.py b/lib/spack/spack/hooks/extensions.py
index bcbd68dfa0..070b309a43 100644
--- a/lib/spack/spack/hooks/extensions.py
+++ b/lib/spack/spack/hooks/extensions.py
@@ -23,8 +23,6 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 
-import spack
-
 
 def pre_uninstall(pkg):
     assert(pkg.spec.concrete)
diff --git a/lib/spack/spack/mirror.py b/lib/spack/spack/mirror.py
index 0bbcfba6b4..f053e4405f 100644
--- a/lib/spack/spack/mirror.py
+++ b/lib/spack/spack/mirror.py
@@ -40,9 +40,8 @@ import spack.error
 import spack.url as url
 import spack.fetch_strategy as fs
 from spack.spec import Spec
-from spack.stage import Stage
 from spack.version import *
-from spack.util.compression import extension, allowed_archive
+from spack.util.compression import allowed_archive
 
 
 def mirror_archive_filename(spec, fetcher):
@@ -52,10 +51,10 @@ def mirror_archive_filename(spec, fetcher):
 
     if isinstance(fetcher, fs.URLFetchStrategy):
         if fetcher.expand_archive:
-            # If we fetch this version with a URLFetchStrategy, use URL's archive type
+            # If we fetch with a URLFetchStrategy, use URL's archive type
             ext = url.downloaded_file_extension(fetcher.url)
         else:
-            # If the archive shouldn't be expanded, don't check for its extension.
+            # If the archive shouldn't be expanded, don't check extension.
             ext = None
     else:
         # Otherwise we'll make a .tar.gz ourselves
@@ -106,7 +105,9 @@ def get_matching_versions(specs, **kwargs):
 
 def suggest_archive_basename(resource):
     """
-    Return a tentative basename for an archive. Raise an exception if the name is among the allowed archive types.
+    Return a tentative basename for an archive.
+
+    Raises an exception if the name is not an allowed archive type.
 
     :param fetcher:
     :return:
@@ -170,7 +171,7 @@ def create(path, specs, **kwargs):
         'error': []
     }
 
-    # Iterate through packages and download all the safe tarballs for each of them
+    # Iterate through packages and download all safe tarballs for each
     for spec in version_specs:
         add_single_spec(spec, mirror_root, categories, **kwargs)
 
@@ -190,12 +191,15 @@ def add_single_spec(spec, mirror_root, categories, **kwargs):
                 fetcher = stage.fetcher
                 if ii == 0:
                     # create a subdirectory for the current package@version
-                    archive_path = os.path.abspath(join_path(mirror_root, mirror_archive_path(spec, fetcher)))
+                    archive_path = os.path.abspath(join_path(
+                        mirror_root, mirror_archive_path(spec, fetcher)))
                     name = spec.format("$_$@")
                 else:
                     resource = stage.resource
-                    archive_path = join_path(subdir, suggest_archive_basename(resource))
-                    name = "{resource} ({pkg}).".format(resource=resource.name, pkg=spec.format("$_$@"))
+                    archive_path = join_path(
+                        subdir, suggest_archive_basename(resource))
+                    name = "{resource} ({pkg}).".format(
+                        resource=resource.name, pkg=spec.format("$_$@"))
                 subdir = os.path.dirname(archive_path)
                 mkdirp(subdir)
 
@@ -217,15 +221,18 @@ def add_single_spec(spec, mirror_root, categories, **kwargs):
             categories['present'].append(spec)
         else:
             categories['mirrored'].append(spec)
+
     except Exception as e:
         if spack.debug:
             sys.excepthook(*sys.exc_info())
         else:
-            tty.warn("Error while fetching %s" % spec.format('$_$@'), e.message)
+            tty.warn("Error while fetching %s"
+                     % spec.format('$_$@'), e.message)
         categories['error'].append(spec)
 
 
 class MirrorError(spack.error.SpackError):
     """Superclass of all mirror-creation related errors."""
+
     def __init__(self, msg, long_msg=None):
         super(MirrorError, self).__init__(msg, long_msg)
diff --git a/lib/spack/spack/modules.py b/lib/spack/spack/modules.py
index 8ac6a77d13..debc6752b4 100644
--- a/lib/spack/spack/modules.py
+++ b/lib/spack/spack/modules.py
@@ -459,7 +459,8 @@ class EnvModule(object):
                 yield self.environment_modifications_formats[type(
                     command)].format(**command.args)
             except KeyError:
-                message = 'Cannot handle command of type {command} : skipping request'  # NOQA: ignore=E501
+                message = ('Cannot handle command of type {command}: '
+                           'skipping request')
                 details = '{context} at {filename}:{lineno}'
                 tty.warn(message.format(command=type(command)))
                 tty.warn(details.format(**command.args))
@@ -494,7 +495,8 @@ class Dotkit(EnvModule):
 
     autoload_format = 'dk_op {module_file}\n'
 
-    default_naming_format = '{name}-{version}-{compiler.name}-{compiler.version}'  # NOQA: ignore=E501
+    default_naming_format = \
+        '{name}-{version}-{compiler.name}-{compiler.version}'
 
     @property
     def file_name(self):
@@ -543,7 +545,8 @@ class TclModule(EnvModule):
 
     prerequisite_format = 'prereq {module_file}\n'
 
-    default_naming_format = '{name}-{version}-{compiler.name}-{compiler.version}'  # NOQA: ignore=E501
+    default_naming_format = \
+        '{name}-{version}-{compiler.name}-{compiler.version}'
 
     @property
     def file_name(self):
@@ -554,7 +557,7 @@ class TclModule(EnvModule):
         timestamp = datetime.datetime.now()
         # TCL Modulefile header
         header = '#%Module1.0\n'
-        header += '## Module file created by spack (https://github.com/LLNL/spack) on %s\n' % timestamp  # NOQA: ignore=E501
+        header += '## Module file created by spack (https://github.com/LLNL/spack) on %s\n' % timestamp
         header += '##\n'
         header += '## %s\n' % self.spec.short_spec
         header += '##\n'
@@ -584,10 +587,12 @@ class TclModule(EnvModule):
                 for naming_dir, conflict_dir in zip(
                         self.naming_scheme.split('/'), item.split('/')):
                     if naming_dir != conflict_dir:
-                        message = 'conflict scheme does not match naming scheme [{spec}]\n\n'  # NOQA: ignore=E501
+                        message = 'conflict scheme does not match naming '
+                        message += 'scheme [{spec}]\n\n'
                         message += 'naming scheme   : "{nformat}"\n'
                         message += 'conflict scheme : "{cformat}"\n\n'
-                        message += '** You may want to check your `modules.yaml` configuration file **\n'  # NOQA: ignore=E501
+                        message += '** You may want to check your '
+                        message += '`modules.yaml` configuration file **\n'
                         tty.error(message.format(spec=self.spec,
                                                  nformat=self.naming_scheme,
                                                  cformat=item))
diff --git a/lib/spack/spack/multimethod.py b/lib/spack/spack/multimethod.py
index 0818f9092f..d1d1f32445 100644
--- a/lib/spack/spack/multimethod.py
+++ b/lib/spack/spack/multimethod.py
@@ -43,15 +43,13 @@ avoids overly complicated rat nests of if statements.  Obviously,
 depending on the scenario, regular old conditionals might be clearer,
 so package authors should use their judgement.
 """
-import sys
 import functools
-import collections
 
 from llnl.util.lang import *
 
 import spack.architecture
 import spack.error
-from spack.spec import parse_anonymous_spec, Spec
+from spack.spec import parse_anonymous_spec
 
 
 class SpecMultiMethod(object):
@@ -89,13 +87,13 @@ class SpecMultiMethod(object):
 
        See the docs for decorators below for more details.
     """
+
     def __init__(self, default=None):
         self.method_list = []
         self.default = default
         if default:
             functools.update_wrapper(self, default)
 
-
     def register(self, spec, method):
         """Register a version of a method for a particular sys_type."""
         self.method_list.append((spec, method))
@@ -105,12 +103,10 @@ class SpecMultiMethod(object):
         else:
             assert(self.__name__ == method.__name__)
 
-
     def __get__(self, obj, objtype):
         """This makes __call__ support instance methods."""
         return functools.partial(self.__call__, obj)
 
-
     def __call__(self, package_self, *args, **kwargs):
         """Find the first method with a spec that matches the
            package's spec.  If none is found, call the default
@@ -127,7 +123,6 @@ class SpecMultiMethod(object):
                 type(package_self), self.__name__, spec,
                 [m[0] for m in self.method_list])
 
-
     def __str__(self):
         return "SpecMultiMethod {\n\tdefault: %s,\n\tspecs: %s\n}" % (
             self.default, self.method_list)
@@ -195,11 +190,13 @@ class when(object):
        platform-specific versions.  There's not much we can do to get
        around this because of the way decorators work.
     """
+
     def __init__(self, spec):
         pkg = get_calling_module_name()
         if spec is True:
             spec = pkg
-        self.spec = parse_anonymous_spec(spec, pkg) if spec is not False else None
+        self.spec = (parse_anonymous_spec(spec, pkg)
+                     if spec is not False else None)
 
     def __call__(self, method):
         # Get the first definition of the method in the calling scope
@@ -218,12 +215,14 @@ class when(object):
 
 class MultiMethodError(spack.error.SpackError):
     """Superclass for multimethod dispatch errors"""
+
     def __init__(self, message):
         super(MultiMethodError, self).__init__(message)
 
 
 class NoSuchMethodError(spack.error.SpackError):
     """Raised when we can't find a version of a multi-method."""
+
     def __init__(self, cls, method_name, spec, possible_specs):
         super(NoSuchMethodError, self).__init__(
             "Package %s does not support %s called with %s.  Options are: %s"
diff --git a/lib/spack/spack/operating_systems/cnl.py b/lib/spack/spack/operating_systems/cnl.py
index dbd2775861..78807865b3 100644
--- a/lib/spack/spack/operating_systems/cnl.py
+++ b/lib/spack/spack/operating_systems/cnl.py
@@ -15,6 +15,7 @@ class Cnl(OperatingSystem):
     modules. If updated, user must make sure that version and name are
     updated to indicate that OS has been upgraded (or downgraded)
     """
+
     def __init__(self):
         name = 'CNL'
         version = '10'
diff --git a/lib/spack/spack/operating_systems/linux_distro.py b/lib/spack/spack/operating_systems/linux_distro.py
index 2e3c72719b..6d70ae80b6 100644
--- a/lib/spack/spack/operating_systems/linux_distro.py
+++ b/lib/spack/spack/operating_systems/linux_distro.py
@@ -2,6 +2,7 @@ import re
 import platform as py_platform
 from spack.architecture import OperatingSystem
 
+
 class LinuxDistro(OperatingSystem):
     """ This class will represent the autodetected operating system
         for a Linux System. Since there are many different flavors of
@@ -9,6 +10,7 @@ class LinuxDistro(OperatingSystem):
         autodetection using the python module platform and the method
         platform.dist()
     """
+
     def __init__(self):
         distname, version, _ = py_platform.linux_distribution(
             full_distribution_name=False)
diff --git a/lib/spack/spack/operating_systems/mac_os.py b/lib/spack/spack/operating_systems/mac_os.py
index f35b3ca577..3e5ab9b2e9 100644
--- a/lib/spack/spack/operating_systems/mac_os.py
+++ b/lib/spack/spack/operating_systems/mac_os.py
@@ -1,6 +1,7 @@
 import platform as py_platform
 from spack.architecture import OperatingSystem
 
+
 class MacOs(OperatingSystem):
     """This class represents the macOS operating system. This will be
     auto detected using the python platform.mac_ver. The macOS
diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 25e07541d0..ff8c8e96bc 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -34,6 +34,7 @@ rundown on spack and how it differs from homebrew, look at the
 README.
 """
 import os
+import sys
 import re
 import textwrap
 import time
@@ -178,12 +179,10 @@ class Package(object):
 
     Most software comes in nicely packaged tarballs, like this one:
         http://www.cmake.org/files/v2.8/cmake-2.8.10.2.tar.gz
-
     Taking a page from homebrew, spack deduces pretty much everything it
     needs to know from the URL above.  If you simply type this:
 
         spack create http://www.cmake.org/files/v2.8/cmake-2.8.10.2.tar.gz
-
     Spack will download the tarball, generate an md5 hash, figure out the
     version and the name of the package from the URL, and create a new
     package file for you with all the names and attributes set correctly.
@@ -705,13 +704,13 @@ class Package(object):
 
             # Ask the user whether to skip the checksum if we're
             # interactive, but just fail if non-interactive.
-            checksum_msg = "Add a checksum or use --no-checksum to skip this check."  # NOQA: ignore=E501
+            ck_msg = "Add a checksum or use --no-checksum to skip this check."
             ignore_checksum = False
             if sys.stdout.isatty():
                 ignore_checksum = tty.get_yes_or_no("  Fetch anyway?",
                                                     default=False)
                 if ignore_checksum:
-                    tty.msg("Fetching with no checksum.", checksum_msg)
+                    tty.msg("Fetching with no checksum.", ck_msg)
 
             if not ignore_checksum:
                 raise FetchError("Will not fetch %s" %
@@ -1305,9 +1304,10 @@ class Package(object):
                     continue
                 for dep in aspec.traverse(deptype='run'):
                     if self.spec == dep:
+                        msg = ("Cannot deactivate %s because %s is activated "
+                               "and depends on it.")
                         raise ActivationError(
-                            "Cannot deactivate %s because %s is activated and depends on it."  # NOQA: ignore=E501
-                            % (self.spec.short_spec, aspec.short_spec))
+                            msg % (self.spec.short_spec, aspec.short_spec))
 
         self.extendee_spec.package.deactivate(self, **self.extendee_args)
 
@@ -1564,6 +1564,7 @@ def make_executable(path):
 
 
 class CMakePackage(StagedPackage):
+
     def make_make(self):
         import multiprocessing
         # number of jobs spack will to build with.
@@ -1740,12 +1741,14 @@ class ExtensionError(PackageError):
 
 
 class ExtensionConflictError(ExtensionError):
+
     def __init__(self, path):
         super(ExtensionConflictError, self).__init__(
             "Extension blocked by file: %s" % path)
 
 
 class ActivationError(ExtensionError):
+
     def __init__(self, msg, long_msg=None):
         super(ActivationError, self).__init__(msg, long_msg)
 
diff --git a/lib/spack/spack/parse.py b/lib/spack/spack/parse.py
index 8adf957e7f..1b88db2d7c 100644
--- a/lib/spack/spack/parse.py
+++ b/lib/spack/spack/parse.py
@@ -29,6 +29,7 @@ import spack.error
 
 class Token:
     """Represents tokens; generated from input by lexer and fed to parse()."""
+
     def __init__(self, type, value='', start=0, end=0):
         self.type = type
         self.value = value
@@ -51,11 +52,13 @@ class Token:
 
 class Lexer(object):
     """Base class for Lexers that keep track of line numbers."""
+
     def __init__(self, lexicon):
         self.scanner = re.Scanner(lexicon)
 
     def token(self, type, value=''):
-        return Token(type, value, self.scanner.match.start(0), self.scanner.match.end(0))
+        return Token(type, value,
+                     self.scanner.match.start(0), self.scanner.match.end(0))
 
     def lex(self, text):
         tokens, remainder = self.scanner.scan(text)
@@ -66,10 +69,11 @@ class Lexer(object):
 
 class Parser(object):
     """Base class for simple recursive descent parsers."""
+
     def __init__(self, lexer):
-        self.tokens = iter([])   # iterators over tokens, handled in order.  Starts empty.
-        self.token = Token(None) # last accepted token starts at beginning of file
-        self.next = None         # next token
+        self.tokens = iter([])    # iterators over tokens, handled in order.
+        self.token = Token(None)  # last accepted token
+        self.next = None          # next token
         self.lexer = lexer
         self.text = None
 
@@ -82,11 +86,12 @@ class Parser(object):
 
     def push_tokens(self, iterable):
         """Adds all tokens in some iterable to the token stream."""
-        self.tokens = itertools.chain(iter(iterable), iter([self.next]), self.tokens)
+        self.tokens = itertools.chain(
+            iter(iterable), iter([self.next]), self.tokens)
         self.gettok()
 
     def accept(self, id):
-        """Puts the next symbol in self.token if we like it.  Then calls gettok()"""
+        """Put the next symbol in self.token if accepted, then call gettok()"""
         if self.next and self.next.is_a(id):
             self.token = self.next
             self.gettok()
@@ -124,9 +129,9 @@ class Parser(object):
         return self.do_parse()
 
 
-
 class ParseError(spack.error.SpackError):
     """Raised when we don't hit an error while parsing."""
+
     def __init__(self, message, string, pos):
         super(ParseError, self).__init__(message)
         self.string = string
@@ -135,5 +140,6 @@ class ParseError(spack.error.SpackError):
 
 class LexError(ParseError):
     """Raised when we don't know how to lex something."""
+
     def __init__(self, message, string, pos):
         super(LexError, self).__init__(message, string, pos)
diff --git a/lib/spack/spack/patch.py b/lib/spack/spack/patch.py
index c2e181be2f..0bd9f5d29d 100644
--- a/lib/spack/spack/patch.py
+++ b/lib/spack/spack/patch.py
@@ -24,7 +24,6 @@
 ##############################################################################
 import os
 
-import llnl.util.tty as tty
 from llnl.util.filesystem import join_path
 
 import spack
@@ -59,7 +58,6 @@ class Patch(object):
             if not os.path.isfile(self.path):
                 raise NoSuchPatchFileError(pkg_name, self.path)
 
-
     def apply(self, stage):
         """Fetch this patch, if necessary, and apply it to the source
            code in the supplied stage.
@@ -84,9 +82,9 @@ class Patch(object):
                 patch_stage.destroy()
 
 
-
 class NoSuchPatchFileError(spack.error.SpackError):
     """Raised when user specifies a patch file that doesn't exist."""
+
     def __init__(self, package, path):
         super(NoSuchPatchFileError, self).__init__(
             "No such patch file for package %s: %s" % (package, path))
diff --git a/lib/spack/spack/platforms/bgq.py b/lib/spack/spack/platforms/bgq.py
index e0eb76f336..91afdd04db 100644
--- a/lib/spack/spack/platforms/bgq.py
+++ b/lib/spack/spack/platforms/bgq.py
@@ -1,6 +1,7 @@
 import os
 from spack.architecture import Platform, Target
 
+
 class Bgq(Platform):
     priority    = 30
     front_end   = 'power7'
@@ -15,4 +16,3 @@ class Bgq(Platform):
     @classmethod
     def detect(self):
         return os.path.exists('/bgsys')
-    
diff --git a/lib/spack/spack/platforms/darwin.py b/lib/spack/spack/platforms/darwin.py
index d47dd640f9..974ce3a3f9 100644
--- a/lib/spack/spack/platforms/darwin.py
+++ b/lib/spack/spack/platforms/darwin.py
@@ -2,6 +2,7 @@ import subprocess
 from spack.architecture import Platform, Target
 from spack.operating_systems.mac_os import MacOs
 
+
 class Darwin(Platform):
     priority    = 89
     front_end   = 'x86_64'
@@ -21,6 +22,6 @@ class Darwin(Platform):
 
     @classmethod
     def detect(self):
-        platform = subprocess.Popen(['uname', '-a'], stdout = subprocess.PIPE)
+        platform = subprocess.Popen(['uname', '-a'], stdout=subprocess.PIPE)
         platform, _ = platform.communicate()
         return 'darwin' in platform.strip().lower()
diff --git a/lib/spack/spack/platforms/linux.py b/lib/spack/spack/platforms/linux.py
index 4d3f59c320..38d2cdbfec 100644
--- a/lib/spack/spack/platforms/linux.py
+++ b/lib/spack/spack/platforms/linux.py
@@ -3,6 +3,7 @@ import platform
 from spack.architecture import Platform, Target
 from spack.operating_systems.linux_distro import LinuxDistro
 
+
 class Linux(Platform):
     priority    = 90
 
@@ -26,6 +27,6 @@ class Linux(Platform):
 
     @classmethod
     def detect(self):
-        platform = subprocess.Popen(['uname', '-a'], stdout = subprocess.PIPE)
+        platform = subprocess.Popen(['uname', '-a'], stdout=subprocess.PIPE)
         platform, _ = platform.communicate()
         return 'linux' in platform.strip().lower()
diff --git a/lib/spack/spack/platforms/test.py b/lib/spack/spack/platforms/test.py
index 8fa2585a7a..c918211555 100644
--- a/lib/spack/spack/platforms/test.py
+++ b/lib/spack/spack/platforms/test.py
@@ -1,4 +1,27 @@
-import subprocess
+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
 from spack.architecture import Platform, Target
 from spack.operating_systems.linux_distro import LinuxDistro
 from spack.operating_systems.cnl import Cnl
@@ -9,7 +32,7 @@ class Test(Platform):
     front_end   = 'x86_32'
     back_end    = 'x86_64'
     default     = 'x86_64'
-    
+
     back_os = 'CNL10'
     default_os = 'CNL10'
 
diff --git a/lib/spack/spack/preferred_packages.py b/lib/spack/spack/preferred_packages.py
index f079c1ef8b..45a41c8e2b 100644
--- a/lib/spack/spack/preferred_packages.py
+++ b/lib/spack/spack/preferred_packages.py
@@ -156,7 +156,7 @@ class PreferredPackages(object):
         """Return True iff the named package has a list of preferred
            providers"""
         return bool(self._order_for_package(pkgname, 'providers',
-                    provider_str, False))
+                                            provider_str, False))
 
     def spec_preferred_variants(self, pkgname):
         """Return a VariantMap of preferred variants and their values"""
diff --git a/lib/spack/spack/provider_index.py b/lib/spack/spack/provider_index.py
index b5fbb67c6e..3f9cd285e7 100644
--- a/lib/spack/spack/provider_index.py
+++ b/lib/spack/spack/provider_index.py
@@ -52,6 +52,7 @@ class ProviderIndex(object):
        matching implementation of MPI.
 
     """
+
     def __init__(self, specs=None, restrict=False):
         """Create a new ProviderIndex.
 
diff --git a/lib/spack/spack/repository.py b/lib/spack/spack/repository.py
index d751a98b35..2d8dc39648 100644
--- a/lib/spack/spack/repository.py
+++ b/lib/spack/spack/repository.py
@@ -68,6 +68,7 @@ NOT_PROVIDED = object()
 def _autospec(function):
     """Decorator that automatically converts the argument of a single-arg
        function to a Spec."""
+
     def converter(self, spec_like, *args, **kwargs):
         if not isinstance(spec_like, spack.spec.Spec):
             spec_like = spack.spec.Spec(spec_like)
@@ -77,6 +78,7 @@ def _autospec(function):
 
 class SpackNamespace(ModuleType):
     """ Allow lazy loading of modules."""
+
     def __init__(self, namespace):
         super(SpackNamespace, self).__init__(namespace)
         self.__file__ = "(spack namespace)"
@@ -112,6 +114,7 @@ class RepoPath(object):
        combined results of the Repos in its list instead of on a
        single package repository.
     """
+
     def __init__(self, *repo_dirs, **kwargs):
         # super-namespace for all packages in the RepoPath
         self.super_namespace = kwargs.get('namespace', repo_namespace)
@@ -360,6 +363,7 @@ class Repo(object):
         A Python namespace where the repository's packages should live.
 
     """
+
     def __init__(self, root, namespace=repo_namespace):
         """Instantiate a package repository from a filesystem path.
 
@@ -923,6 +927,7 @@ class PackageLoadError(spack.error.SpackError):
 
 class UnknownPackageError(PackageLoadError):
     """Raised when we encounter a package spack doesn't have."""
+
     def __init__(self, name, repo=None):
         msg = None
         if repo:
@@ -935,6 +940,7 @@ class UnknownPackageError(PackageLoadError):
 
 class UnknownNamespaceError(PackageLoadError):
     """Raised when we encounter an unknown namespace"""
+
     def __init__(self, namespace):
         super(UnknownNamespaceError, self).__init__(
             "Unknown namespace: %s" % namespace)
@@ -942,6 +948,7 @@ class UnknownNamespaceError(PackageLoadError):
 
 class FailedConstructorError(PackageLoadError):
     """Raised when a package's class constructor fails."""
+
     def __init__(self, name, exc_type, exc_obj, exc_tb):
         super(FailedConstructorError, self).__init__(
             "Class constructor failed for package '%s'." % name,
diff --git a/lib/spack/spack/resource.py b/lib/spack/spack/resource.py
index 24b675f8da..1d4d448298 100644
--- a/lib/spack/spack/resource.py
+++ b/lib/spack/spack/resource.py
@@ -31,9 +31,11 @@ package to enable optional features.
 
 
 class Resource(object):
+    """Represents an optional resource to be fetched by a package.
+
+    Aggregates a name, a fetcher, a destination and a placement.
     """
-    Represents an optional resource. Aggregates a name, a fetcher, a destination and a placement
-    """
+
     def __init__(self, name, fetcher, destination, placement):
         self.name = name
         self.fetcher = fetcher
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index a37b39be67..0d72d454c6 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -166,6 +166,7 @@ def colorize_spec(spec):
     """Returns a spec colorized according to the colors specified in
        color_formats."""
     class insert_color:
+
         def __init__(self):
             self.last = None
 
@@ -186,6 +187,7 @@ class CompilerSpec(object):
     """The CompilerSpec field represents the compiler or range of compiler
        versions that a package should be built with.  CompilerSpecs have a
        name and a version list. """
+
     def __init__(self, *args):
         nargs = len(args)
         if nargs == 1:
@@ -296,6 +298,7 @@ class DependencySpec(object):
     - spec: the spack.spec.Spec description of a dependency.
     - deptypes: strings representing the type of dependency this is.
     """
+
     def __init__(self, spec, deptypes):
         self.spec = spec
         self.deptypes = deptypes
@@ -317,6 +320,7 @@ class VariantSpec(object):
        on the particular package being built, and each named variant can
        be enabled or disabled.
     """
+
     def __init__(self, name, value):
         self.name = name
         self.value = value
@@ -447,9 +451,9 @@ class FlagMap(HashableMap):
         sorted_keys = filter(
             lambda flag: self[flag] != [], sorted(self.keys()))
         cond_symbol = ' ' if len(sorted_keys) > 0 else ''
-        return cond_symbol + ' '.join(str(key) + '=\"' + ' '.join(str(f)
-                                      for f in self[key]) + '\"'
-                                      for key in sorted_keys)
+        return cond_symbol + ' '.join(
+            str(key) + '=\"' + ' '.join(
+                str(f) for f in self[key]) + '\"' for key in sorted_keys)
 
 
 class DependencyMap(HashableMap):
@@ -910,7 +914,7 @@ class Spec(object):
 
         params = dict((name, v.value) for name, v in self.variants.items())
         params.update(dict((name, value)
-                      for name, value in self.compiler_flags.items()))
+                           for name, value in self.compiler_flags.items()))
 
         if params:
             d['parameters'] = params
@@ -1598,8 +1602,8 @@ class Spec(object):
             raise UnsatisfiableSpecNameError(self.name, other.name)
 
         if (other.namespace is not None and
-           self.namespace is not None and
-           other.namespace != self.namespace):
+                self.namespace is not None and
+                other.namespace != self.namespace):
             raise UnsatisfiableSpecNameError(self.fullname, other.fullname)
 
         if not self.versions.overlaps(other.versions):
@@ -1753,8 +1757,8 @@ class Spec(object):
 
         # namespaces either match, or other doesn't require one.
         if (other.namespace is not None and
-            self.namespace is not None and
-           self.namespace != other.namespace):
+                self.namespace is not None and
+                self.namespace != other.namespace):
             return False
         if self.versions and other.versions:
             if not self.versions.satisfies(other.versions, strict=strict):
@@ -1849,7 +1853,7 @@ class Spec(object):
         # compatible with mpich2)
         for spec in self.virtual_dependencies():
             if (spec.name in other_index and
-               not other_index.providers_for(spec)):
+                    not other_index.providers_for(spec)):
                 return False
 
         for spec in other.virtual_dependencies():
@@ -2345,6 +2349,7 @@ _lexer = SpecLexer()
 
 
 class SpecParser(spack.parse.Parser):
+
     def __init__(self):
         super(SpecParser, self).__init__(_lexer)
         self.previous = None
diff --git a/lib/spack/spack/test/architecture.py b/lib/spack/spack/test/architecture.py
index b8441bdac4..22ddd4c97e 100644
--- a/lib/spack/spack/test/architecture.py
+++ b/lib/spack/spack/test/architecture.py
@@ -40,6 +40,7 @@ from spack.test.mock_packages_test import *
 
 
 class ArchitectureTest(MockPackagesTest):
+
     def setUp(self):
         super(ArchitectureTest, self).setUp()
         self.platform = spack.architecture.platform()
diff --git a/lib/spack/spack/test/cc.py b/lib/spack/spack/test/cc.py
index ea2b164462..f3e4bb31d2 100644
--- a/lib/spack/spack/test/cc.py
+++ b/lib/spack/spack/test/cc.py
@@ -45,7 +45,8 @@ test_command = [
     '-llib1', '-llib2',
     'arg4',
     '-Wl,--end-group',
-    '-Xlinker', '-rpath', '-Xlinker', '/third/rpath', '-Xlinker', '-rpath', '-Xlinker', '/fourth/rpath',
+    '-Xlinker', '-rpath', '-Xlinker', '/third/rpath', '-Xlinker',
+    '-rpath', '-Xlinker', '/fourth/rpath',
     '-llib3', '-llib4',
     'arg5', 'arg6']
 
@@ -67,7 +68,7 @@ class CompilerTest(unittest.TestCase):
         os.environ['SPACK_FC'] = self.realcc
 
         os.environ['SPACK_PREFIX'] = self.prefix
-        os.environ['SPACK_ENV_PATH']="test"
+        os.environ['SPACK_ENV_PATH'] = "test"
         os.environ['SPACK_DEBUG_LOG_DIR'] = "."
         os.environ['SPACK_COMPILER_SPEC'] = "gcc@4.4.7"
         os.environ['SPACK_SHORT_SPEC'] = "foo@1.2"
@@ -97,16 +98,13 @@ class CompilerTest(unittest.TestCase):
         if 'SPACK_DEPENDENCIES' in os.environ:
             del os.environ['SPACK_DEPENDENCIES']
 
-
     def tearDown(self):
         shutil.rmtree(self.tmp_deps, True)
 
-
     def check_cc(self, command, args, expected):
         os.environ['SPACK_TEST_COMMAND'] = command
         self.assertEqual(self.cc(*args, output=str).strip(), expected)
 
-
     def check_cxx(self, command, args, expected):
         os.environ['SPACK_TEST_COMMAND'] = command
         self.assertEqual(self.cxx(*args, output=str).strip(), expected)
@@ -115,46 +113,46 @@ class CompilerTest(unittest.TestCase):
         os.environ['SPACK_TEST_COMMAND'] = command
         self.assertEqual(self.fc(*args, output=str).strip(), expected)
 
-
     def check_ld(self, command, args, expected):
         os.environ['SPACK_TEST_COMMAND'] = command
         self.assertEqual(self.ld(*args, output=str).strip(), expected)
 
-
     def check_cpp(self, command, args, expected):
         os.environ['SPACK_TEST_COMMAND'] = command
         self.assertEqual(self.cpp(*args, output=str).strip(), expected)
 
-
     def test_vcheck_mode(self):
         self.check_cc('dump-mode', ['-I/include', '--version'], "vcheck")
         self.check_cc('dump-mode', ['-I/include', '-V'], "vcheck")
         self.check_cc('dump-mode', ['-I/include', '-v'], "vcheck")
         self.check_cc('dump-mode', ['-I/include', '-dumpversion'], "vcheck")
         self.check_cc('dump-mode', ['-I/include', '--version', '-c'], "vcheck")
-        self.check_cc('dump-mode', ['-I/include', '-V', '-o', 'output'], "vcheck")
-
+        self.check_cc('dump-mode', ['-I/include',
+                                    '-V', '-o', 'output'], "vcheck")
 
     def test_cpp_mode(self):
         self.check_cc('dump-mode', ['-E'], "cpp")
         self.check_cpp('dump-mode', [], "cpp")
 
-
     def test_as_mode(self):
         self.check_cc('dump-mode', ['-S'], "as")
 
-
     def test_ccld_mode(self):
         self.check_cc('dump-mode', [], "ccld")
         self.check_cc('dump-mode', ['foo.c', '-o', 'foo'], "ccld")
-        self.check_cc('dump-mode', ['foo.c', '-o', 'foo', '-Wl,-rpath,foo'], "ccld")
-        self.check_cc('dump-mode', ['foo.o', 'bar.o', 'baz.o', '-o', 'foo', '-Wl,-rpath,foo'], "ccld")
-
+        self.check_cc('dump-mode', ['foo.c', '-o',
+                                    'foo', '-Wl,-rpath,foo'], "ccld")
+        self.check_cc(
+            'dump-mode',
+            ['foo.o', 'bar.o', 'baz.o', '-o', 'foo', '-Wl,-rpath,foo'],
+            "ccld")
 
     def test_ld_mode(self):
         self.check_ld('dump-mode', [], "ld")
-        self.check_ld('dump-mode', ['foo.o', 'bar.o', 'baz.o', '-o', 'foo', '-Wl,-rpath,foo'], "ld")
-
+        self.check_ld(
+            'dump-mode',
+            ['foo.o', 'bar.o', 'baz.o', '-o', 'foo', '-Wl,-rpath,foo'],
+            "ld")
 
     def test_flags(self):
         os.environ['SPACK_LDFLAGS'] = '-L foo'
@@ -176,10 +174,11 @@ class CompilerTest(unittest.TestCase):
         # Test cppflags added properly in cpp mode
         self.check_cpp('dump-args', test_command,
                        "cpp " +
-                      '-g -O1 ' +
-                      ' '.join(test_command))
+                       '-g -O1 ' +
+                       ' '.join(test_command))
 
-        # Test ldflags, cppflags, and language specific flags are added in proper order
+        # Test ldflags, cppflags, and language specific flags are added in
+        # proper order
         self.check_cc('dump-args', test_command,
                       self.realcc + ' ' +
                       '-Wl,-rpath,' + self.prefix + '/lib ' +
@@ -191,14 +190,14 @@ class CompilerTest(unittest.TestCase):
                       '-lfoo')
 
         self.check_cxx('dump-args', test_command,
-                      self.realcc + ' ' +
-                      '-Wl,-rpath,' + self.prefix + '/lib ' +
-                      '-Wl,-rpath,' + self.prefix + '/lib64 ' +
-                      '-g -O1 ' +
-                      '-Werror ' +
-                      '-L foo ' +
-                      ' '.join(test_command) + ' ' +
-                      '-lfoo')
+                       self.realcc + ' ' +
+                       '-Wl,-rpath,' + self.prefix + '/lib ' +
+                       '-Wl,-rpath,' + self.prefix + '/lib64 ' +
+                       '-g -O1 ' +
+                       '-Werror ' +
+                       '-L foo ' +
+                       ' '.join(test_command) + ' ' +
+                       '-lfoo')
 
         self.check_fc('dump-args', test_command,
                       self.realcc + ' ' +
@@ -210,9 +209,8 @@ class CompilerTest(unittest.TestCase):
                       ' '.join(test_command) + ' ' +
                       '-lfoo')
 
-        os.environ['SPACK_LDFLAGS']=''
-        os.environ['SPACK_LDLIBS']=''
-
+        os.environ['SPACK_LDFLAGS'] = ''
+        os.environ['SPACK_LDLIBS'] = ''
 
     def test_dep_rpath(self):
         """Ensure RPATHs for root package are added."""
@@ -222,7 +220,6 @@ class CompilerTest(unittest.TestCase):
                       '-Wl,-rpath,' + self.prefix + '/lib64 ' +
                       ' '.join(test_command))
 
-
     def test_dep_include(self):
         """Ensure a single dependency include directory is added."""
         os.environ['SPACK_DEPENDENCIES'] = self.dep4
@@ -233,7 +230,6 @@ class CompilerTest(unittest.TestCase):
                       '-I' + self.dep4 + '/include ' +
                       ' '.join(test_command))
 
-
     def test_dep_lib(self):
         """Ensure a single dependency RPATH is added."""
         os.environ['SPACK_DEPENDENCIES'] = self.dep2
@@ -245,7 +241,6 @@ class CompilerTest(unittest.TestCase):
                       '-Wl,-rpath,' + self.dep2 + '/lib64 ' +
                       ' '.join(test_command))
 
-
     def test_all_deps(self):
         """Ensure includes and RPATHs for all deps are added. """
         os.environ['SPACK_DEPENDENCIES'] = ':'.join([
@@ -274,7 +269,6 @@ class CompilerTest(unittest.TestCase):
 
                       ' '.join(test_command))
 
-
     def test_ld_deps(self):
         """Ensure no (extra) -I args or -Wl, are passed in ld mode."""
         os.environ['SPACK_DEPENDENCIES'] = ':'.join([
diff --git a/lib/spack/spack/test/cmd/module.py b/lib/spack/spack/test/cmd/module.py
index 36a4a73fe6..3a0ce32e6c 100644
--- a/lib/spack/spack/test/cmd/module.py
+++ b/lib/spack/spack/test/cmd/module.py
@@ -33,16 +33,17 @@ import spack.test.mock_database
 class TestModule(spack.test.mock_database.MockDatabase):
 
     def _get_module_files(self, args):
-        return [
-            modules.module_types[args.module_type](spec).file_name for spec in args.specs  # NOQA: ignore=E501
-        ]
+        return [modules.module_types[args.module_type](spec).file_name
+                for spec in args.specs]
 
     def test_module_common_operations(self):
         parser = argparse.ArgumentParser()
         module.setup_parser(parser)
+
         # Try to remove a non existing module [tcl]
         args = parser.parse_args(['rm', 'doesnotexist'])
         self.assertRaises(SystemExit, module.module, parser, args)
+
         # Remove existing modules [tcl]
         args = parser.parse_args(['rm', '-y', 'mpileaks'])
         module_files = self._get_module_files(args)
@@ -51,22 +52,28 @@ class TestModule(spack.test.mock_database.MockDatabase):
         module.module(parser, args)
         for item in module_files:
             self.assertFalse(os.path.exists(item))
+
         # Add them back [tcl]
         args = parser.parse_args(['refresh', '-y', 'mpileaks'])
         module.module(parser, args)
         for item in module_files:
             self.assertTrue(os.path.exists(item))
+
         # TODO : test the --delete-tree option
         # TODO : this requires having a separate directory for test modules
+
         # Try to find a module with multiple matches
         args = parser.parse_args(['find', 'mpileaks'])
         self.assertRaises(SystemExit, module.module, parser, args)
+
         # Try to find a module with no matches
         args = parser.parse_args(['find', 'doesnotexist'])
         self.assertRaises(SystemExit, module.module, parser, args)
+
         # Try to find a module
         args = parser.parse_args(['find', 'libelf'])
         module.module(parser, args)
+
         # Remove existing modules [dotkit]
         args = parser.parse_args(['rm', '-y', '-m', 'dotkit', 'mpileaks'])
         module_files = self._get_module_files(args)
@@ -75,6 +82,7 @@ class TestModule(spack.test.mock_database.MockDatabase):
         module.module(parser, args)
         for item in module_files:
             self.assertFalse(os.path.exists(item))
+
         # Add them back [dotkit]
         args = parser.parse_args(['refresh', '-y', '-m', 'dotkit', 'mpileaks'])
         module.module(parser, args)
diff --git a/lib/spack/spack/test/cmd/test_compiler_cmd.py b/lib/spack/spack/test/cmd/test_compiler_cmd.py
index d89814154b..fa806ee6f4 100644
--- a/lib/spack/spack/test/cmd/test_compiler_cmd.py
+++ b/lib/spack/spack/test/cmd/test_compiler_cmd.py
@@ -12,7 +12,9 @@ from spack.test.mock_packages_test import *
 
 test_version = '4.5-spacktest'
 
+
 class MockArgs(object):
+
     def __init__(self, add_paths=[], scope=None, compiler_spec=None, all=None):
         self.add_paths = add_paths
         self.scope = scope
@@ -52,14 +54,12 @@ done
 class CompilerCmdTest(MockPackagesTest):
     """ Test compiler commands for add and remove """
 
-
     def test_compiler_remove(self):
         args = MockArgs(all=True, compiler_spec='gcc@4.5.0')
         spack.cmd.compiler.compiler_remove(args)
         compilers = spack.compilers.all_compilers()
         self.assertTrue(spack.spec.CompilerSpec("gcc@4.5.0") not in compilers)
 
-
     def test_compiler_add(self):
         # compilers available by default.
         old_compilers = set(spack.compilers.all_compilers())
@@ -75,7 +75,8 @@ class CompilerCmdTest(MockPackagesTest):
             new_compilers = set(spack.compilers.all_compilers())
             new_compiler = new_compilers - old_compilers
             self.assertTrue(new_compiler)
-            self.assertTrue(new_compiler.pop().version == Version(test_version))
+            self.assertTrue(new_compiler.pop().version ==
+                            Version(test_version))
 
         finally:
             shutil.rmtree(compiler_dir, ignore_errors=True)
diff --git a/lib/spack/spack/test/cmd/uninstall.py b/lib/spack/spack/test/cmd/uninstall.py
index 9fffaace40..4ccb9ddbf4 100644
--- a/lib/spack/spack/test/cmd/uninstall.py
+++ b/lib/spack/spack/test/cmd/uninstall.py
@@ -28,6 +28,7 @@ from spack.cmd.uninstall import uninstall
 
 
 class MockArgs(object):
+
     def __init__(self, packages, all=False, force=False, dependents=False):
         self.packages = packages
         self.all = all
@@ -37,6 +38,7 @@ class MockArgs(object):
 
 
 class TestUninstall(spack.test.mock_database.MockDatabase):
+
     def test_uninstall(self):
         parser = None
         # Multiple matches
diff --git a/lib/spack/spack/test/config.py b/lib/spack/spack/test/config.py
index 252d77e66b..0822e44db8 100644
--- a/lib/spack/spack/test/config.py
+++ b/lib/spack/spack/test/config.py
@@ -32,79 +32,80 @@ from ordereddict_backport import OrderedDict
 from spack.test.mock_packages_test import *
 
 # Some sample compiler config data
-a_comps =  [
+a_comps = [
     {'compiler': {
         'paths': {
-            "cc" : "/gcc473",
+            "cc": "/gcc473",
             "cxx": "/g++473",
             "f77": None,
-            "fc" : None 
-            },
+            "fc": None
+        },
         'modules': None,
         'spec': 'gcc@4.7.3',
         'operating_system': 'CNL10'
-        }},
+    }},
     {'compiler': {
         'paths': {
-            "cc" : "/gcc450",
+            "cc": "/gcc450",
             "cxx": "/g++450",
             "f77": 'gfortran',
-            "fc" : 'gfortran'
-            },
+            "fc": 'gfortran'
+        },
         'modules': None,
         'spec': 'gcc@4.5.0',
         'operating_system': 'CNL10'
-        }},
+    }},
     {'compiler': {
         'paths': {
-            "cc" : "<overwritten>",
+            "cc": "<overwritten>",
             "cxx": "<overwritten>",
             "f77": '<overwritten>',
-            "fc" : '<overwritten>' },
+            "fc": '<overwritten>'},
         'modules': None,
         'spec': 'clang@3.3',
         'operating_system': 'CNL10'
-        }}
+    }}
 ]
 
 b_comps = [
     {'compiler': {
         'paths': {
-            "cc" : "/icc100",
+            "cc": "/icc100",
             "cxx": "/icp100",
             "f77": None,
-            "fc" : None
-            },
+            "fc": None
+        },
         'modules': None,
         'spec': 'icc@10.0',
         'operating_system': 'CNL10'
-        }},
+    }},
     {'compiler': {
         'paths': {
-            "cc" : "/icc111",
+            "cc": "/icc111",
             "cxx": "/icp111",
             "f77": 'ifort',
-            "fc" : 'ifort'
-            },
+            "fc": 'ifort'
+        },
         'modules': None,
         'spec': 'icc@11.1',
         'operating_system': 'CNL10'
-        }},
+    }},
     {'compiler': {
         'paths': {
-            "cc" : "<overwritten>",
+            "cc": "<overwritten>",
             "cxx": "<overwritten>",
             "f77": '<overwritten>',
-            "fc" : '<overwritten>' },
+            "fc": '<overwritten>'},
         'modules': None,
         'spec': 'clang@3.3',
         'operating_system': 'CNL10'
-        }}
+    }}
 ]
 
 # Some Sample repo data
-repos_low = [ "/some/path" ]
-repos_high = [ "/some/other/path" ]
+repos_low = ["/some/path"]
+repos_high = ["/some/other/path"]
+
 
 class ConfigTest(MockPackagesTest):
 
@@ -112,14 +113,15 @@ class ConfigTest(MockPackagesTest):
         super(ConfigTest, self).setUp()
         self.tmp_dir = mkdtemp('.tmp', 'spack-config-test-')
         spack.config.config_scopes = OrderedDict()
-        spack.config.ConfigScope('test_low_priority', os.path.join(self.tmp_dir, 'low'))
-        spack.config.ConfigScope('test_high_priority', os.path.join(self.tmp_dir, 'high'))
+        spack.config.ConfigScope(
+            'test_low_priority', os.path.join(self.tmp_dir, 'low'))
+        spack.config.ConfigScope('test_high_priority',
+                                 os.path.join(self.tmp_dir, 'high'))
 
     def tearDown(self):
         super(ConfigTest, self).tearDown()
         shutil.rmtree(self.tmp_dir, True)
 
-
     def check_config(self, comps, *compiler_names):
         """Check that named compilers in comps match Spack's config."""
         config = spack.config.get_config('compilers')
@@ -146,7 +148,7 @@ class ConfigTest(MockPackagesTest):
         spack.config.update_config('repos', repos_low, 'test_low_priority')
         spack.config.update_config('repos', repos_high, 'test_high_priority')
         config = spack.config.get_config('repos')
-        self.assertEqual(config, repos_high+repos_low)
+        self.assertEqual(config, repos_high + repos_low)
 
     def test_write_key_in_memory(self):
         # Write b_comps "on top of" a_comps.
@@ -157,7 +159,6 @@ class ConfigTest(MockPackagesTest):
         self.check_config(a_comps, 'gcc@4.7.3', 'gcc@4.5.0')
         self.check_config(b_comps, 'icc@10.0', 'icc@11.1', 'clang@3.3')
 
-
     def test_write_key_to_disk(self):
         # Write b_comps "on top of" a_comps.
         spack.config.update_config('compilers', a_comps, 'test_low_priority')
diff --git a/lib/spack/spack/test/database.py b/lib/spack/spack/test/database.py
index 0d44a27b7e..22b1f17890 100644
--- a/lib/spack/spack/test/database.py
+++ b/lib/spack/spack/test/database.py
@@ -71,6 +71,7 @@ def _print_ref_counts():
 
 
 class DatabaseTest(MockDatabase):
+
     def test_005_db_exists(self):
         """Make sure db cache file exists after creating."""
         index_file = join_path(self.install_path, '.spack-db', 'index.yaml')
diff --git a/lib/spack/spack/test/directory_layout.py b/lib/spack/spack/test/directory_layout.py
index 74669fe8a2..2d0565acae 100644
--- a/lib/spack/spack/test/directory_layout.py
+++ b/lib/spack/spack/test/directory_layout.py
@@ -49,13 +49,11 @@ class DirectoryLayoutTest(MockPackagesTest):
         self.tmpdir = tempfile.mkdtemp()
         self.layout = YamlDirectoryLayout(self.tmpdir)
 
-
     def tearDown(self):
         super(DirectoryLayoutTest, self).tearDown()
         shutil.rmtree(self.tmpdir, ignore_errors=True)
         self.layout = None
 
-
     def test_read_and_write_spec(self):
         """This goes through each package in spack and creates a directory for
            it.  It then ensures that the spec for the directory's
@@ -67,8 +65,8 @@ class DirectoryLayoutTest(MockPackagesTest):
 
         for pkg in packages:
             if pkg.name.startswith('external'):
-                #External package tests cannot be installed
-                continue            
+                # External package tests cannot be installed
+                continue
             spec = pkg.spec
 
             # If a spec fails to concretize, just skip it.  If it is a
@@ -115,7 +113,6 @@ class DirectoryLayoutTest(MockPackagesTest):
             self.assertFalse(os.path.isdir(install_dir))
             self.assertFalse(os.path.exists(install_dir))
 
-
     def test_handle_unknown_package(self):
         """This test ensures that spack can at least do *some*
            operations with packages that are installed but that it
@@ -166,7 +163,6 @@ class DirectoryLayoutTest(MockPackagesTest):
 
         spack.repo.swap(mock_db)
 
-
     def test_find(self):
         """Test that finding specs within an install layout works."""
         packages = list(spack.repo.all_packages())[:max_packages]
@@ -175,13 +171,14 @@ class DirectoryLayoutTest(MockPackagesTest):
         installed_specs = {}
         for pkg in packages:
             if pkg.name.startswith('external'):
-                #External package tests cannot be installed
+                # External package tests cannot be installed
                 continue
             spec = pkg.spec.concretized()
             installed_specs[spec.name] = spec
             self.layout.create_install_directory(spec)
 
-        # Make sure all the installed specs appear in DirectoryLayout.all_specs()
+        # Make sure all the installed specs appear in
+        # DirectoryLayout.all_specs()
         found_specs = dict((s.name, s) for s in self.layout.all_specs())
         for name, spec in found_specs.items():
             self.assertTrue(name in found_specs)
diff --git a/lib/spack/spack/test/environment.py b/lib/spack/spack/test/environment.py
index 2396961888..9b5d75f273 100644
--- a/lib/spack/spack/test/environment.py
+++ b/lib/spack/spack/test/environment.py
@@ -38,7 +38,8 @@ class EnvironmentTest(unittest.TestCase):
         os.environ['UNSET_ME'] = 'foo'
         os.environ['EMPTY_PATH_LIST'] = ''
         os.environ['PATH_LIST'] = '/path/second:/path/third'
-        os.environ['REMOVE_PATH_LIST'] = '/a/b:/duplicate:/a/c:/remove/this:/a/d:/duplicate/:/f/g'  # NOQA: ignore=E501
+        os.environ['REMOVE_PATH_LIST'] = \
+            '/a/b:/duplicate:/a/c:/remove/this:/a/d:/duplicate/:/f/g'
 
     def tearDown(self):
         pass
diff --git a/lib/spack/spack/test/git_fetch.py b/lib/spack/spack/test/git_fetch.py
index 4de65760d7..0d1a8fe949 100644
--- a/lib/spack/spack/test/git_fetch.py
+++ b/lib/spack/spack/test/git_fetch.py
@@ -87,33 +87,29 @@ class GitFetchTest(MockPackagesTest):
 
             self.assert_rev(rev)
 
-
     def test_fetch_master(self):
         """Test a default git checkout with no commit or tag specified."""
         self.try_fetch('master', self.repo.r0_file, {
-            'git' : self.repo.path
+            'git': self.repo.path
         })
 
-
     def test_fetch_branch(self):
         """Test fetching a branch."""
         self.try_fetch(self.repo.branch, self.repo.branch_file, {
-            'git'    : self.repo.path,
-            'branch' : self.repo.branch
+            'git': self.repo.path,
+            'branch': self.repo.branch
         })
 
-
     def test_fetch_tag(self):
         """Test fetching a tag."""
         self.try_fetch(self.repo.tag, self.repo.tag_file, {
-            'git' : self.repo.path,
-            'tag' : self.repo.tag
+            'git': self.repo.path,
+            'tag': self.repo.tag
         })
 
-
     def test_fetch_commit(self):
         """Test fetching a particular commit."""
         self.try_fetch(self.repo.r1, self.repo.r1_file, {
-            'git'    : self.repo.path,
-            'commit' : self.repo.r1
+            'git': self.repo.path,
+            'commit': self.repo.r1
         })
diff --git a/lib/spack/spack/test/hg_fetch.py b/lib/spack/spack/test/hg_fetch.py
index 292ffba949..44af6730a1 100644
--- a/lib/spack/spack/test/hg_fetch.py
+++ b/lib/spack/spack/test/hg_fetch.py
@@ -83,17 +83,15 @@ class HgFetchTest(MockPackagesTest):
 
             self.assertEqual(self.repo.get_rev(), rev)
 
-
     def test_fetch_default(self):
         """Test a default hg checkout with no commit or tag specified."""
         self.try_fetch(self.repo.r1, self.repo.r1_file, {
-            'hg' : self.repo.path
+            'hg': self.repo.path
         })
 
-
     def test_fetch_rev0(self):
         """Test fetching a branch."""
         self.try_fetch(self.repo.r0, self.repo.r0_file, {
-            'hg'       : self.repo.path,
-            'revision' : self.repo.r0
+            'hg': self.repo.path,
+            'revision': self.repo.r0
         })
diff --git a/lib/spack/spack/test/install.py b/lib/spack/spack/test/install.py
index 390ec096a9..232d5aeeaf 100644
--- a/lib/spack/spack/test/install.py
+++ b/lib/spack/spack/test/install.py
@@ -55,7 +55,6 @@ class InstallTest(MockPackagesTest):
         spack.install_layout = YamlDirectoryLayout(self.tmpdir)
         spack.installed_db   = Database(self.tmpdir)
 
-
     def tearDown(self):
         super(InstallTest, self).tearDown()
         self.repo.destroy()
@@ -68,14 +67,12 @@ class InstallTest(MockPackagesTest):
         spack.installed_db   = self.orig_db
         shutil.rmtree(self.tmpdir, ignore_errors=True)
 
-
     def fake_fetchify(self, pkg):
         """Fake the URL for a package so it downloads from a file."""
         fetcher = FetchStrategyComposite()
         fetcher.append(URLFetchStrategy(self.repo.url))
         pkg.fetcher = fetcher
 
-
     def test_install_and_uninstall(self):
         # Get a basic concrete spec for the trivial install package.
         spec = Spec('trivial_install_test_package')
@@ -90,11 +87,10 @@ class InstallTest(MockPackagesTest):
         try:
             pkg.do_install()
             pkg.do_uninstall()
-        except Exception, e:
+        except Exception:
             pkg.remove_prefix()
             raise
 
-
     def test_install_environment(self):
         spec = Spec('cmake-client').concretized()
 
@@ -104,6 +100,6 @@ class InstallTest(MockPackagesTest):
         pkg = spec.package
         try:
             pkg.do_install()
-        except Exception, e:
+        except Exception:
             pkg.remove_prefix()
             raise
diff --git a/lib/spack/spack/test/link_tree.py b/lib/spack/spack/test/link_tree.py
index de40991b57..5d0a7430b6 100644
--- a/lib/spack/spack/test/link_tree.py
+++ b/lib/spack/spack/test/link_tree.py
@@ -53,16 +53,13 @@ class LinkTreeTest(unittest.TestCase):
     def tearDown(self):
         self.stage.destroy()
 
-
     def check_file_link(self, filename):
         self.assertTrue(os.path.isfile(filename))
         self.assertTrue(os.path.islink(filename))
 
-
     def check_dir(self, filename):
         self.assertTrue(os.path.isdir(filename))
 
-
     def test_merge_to_new_directory(self):
         with working_dir(self.stage.path):
             self.link_tree.merge('dest')
@@ -79,7 +76,6 @@ class LinkTreeTest(unittest.TestCase):
 
             self.assertFalse(os.path.exists('dest'))
 
-
     def test_merge_to_existing_directory(self):
         with working_dir(self.stage.path):
 
@@ -112,7 +108,6 @@ class LinkTreeTest(unittest.TestCase):
             self.assertFalse(os.path.isfile('dest/c/d/6'))
             self.assertFalse(os.path.isfile('dest/c/d/e/7'))
 
-
     def test_merge_with_empty_directories(self):
         with working_dir(self.stage.path):
             mkdirp('dest/f/g')
@@ -132,7 +127,6 @@ class LinkTreeTest(unittest.TestCase):
             self.assertTrue(os.path.isdir('dest/a/b/h'))
             self.assertTrue(os.path.isdir('dest/f/g'))
 
-
     def test_ignore(self):
         with working_dir(self.stage.path):
             touchp('source/.spec')
diff --git a/lib/spack/spack/test/lock.py b/lib/spack/spack/test/lock.py
index b24050aa74..fb96539897 100644
--- a/lib/spack/spack/test/lock.py
+++ b/lib/spack/spack/test/lock.py
@@ -329,6 +329,7 @@ class LockTest(unittest.TestCase):
 
     def test_transaction_with_context_manager(self):
         class TestContextManager(object):
+
             def __enter__(self):
                 vals['entered'] = True
 
@@ -388,6 +389,7 @@ class LockTest(unittest.TestCase):
 
     def test_transaction_with_context_manager_and_exception(self):
         class TestContextManager(object):
+
             def __enter__(self):
                 vals['entered'] = True
 
diff --git a/lib/spack/spack/test/make_executable.py b/lib/spack/spack/test/make_executable.py
index b7a45a3f72..87a43a529a 100644
--- a/lib/spack/spack/test/make_executable.py
+++ b/lib/spack/spack/test/make_executable.py
@@ -38,6 +38,7 @@ from spack.util.environment import path_put_first
 
 
 class MakeExecutableTest(unittest.TestCase):
+
     def setUp(self):
         self.tmpdir = tempfile.mkdtemp()
 
@@ -49,34 +50,30 @@ class MakeExecutableTest(unittest.TestCase):
 
         path_put_first('PATH', [self.tmpdir])
 
-
     def tearDown(self):
         shutil.rmtree(self.tmpdir)
 
-
     def test_make_normal(self):
         make = MakeExecutable('make', 8)
         self.assertEqual(make(output=str).strip(), '-j8')
         self.assertEqual(make('install', output=str).strip(), '-j8 install')
 
-
     def test_make_explicit(self):
         make = MakeExecutable('make', 8)
         self.assertEqual(make(parallel=True, output=str).strip(), '-j8')
-        self.assertEqual(make('install', parallel=True, output=str).strip(), '-j8 install')
-
+        self.assertEqual(make('install', parallel=True,
+                              output=str).strip(), '-j8 install')
 
     def test_make_one_job(self):
         make = MakeExecutable('make', 1)
         self.assertEqual(make(output=str).strip(), '')
         self.assertEqual(make('install', output=str).strip(), 'install')
 
-
     def test_make_parallel_false(self):
         make = MakeExecutable('make', 8)
         self.assertEqual(make(parallel=False, output=str).strip(), '')
-        self.assertEqual(make('install', parallel=False, output=str).strip(), 'install')
-
+        self.assertEqual(make('install', parallel=False,
+                              output=str).strip(), 'install')
 
     def test_make_parallel_disabled(self):
         make = MakeExecutable('make', 8)
@@ -100,26 +97,29 @@ class MakeExecutableTest(unittest.TestCase):
 
         del os.environ['SPACK_NO_PARALLEL_MAKE']
 
-
     def test_make_parallel_precedence(self):
         make = MakeExecutable('make', 8)
 
         # These should work
         os.environ['SPACK_NO_PARALLEL_MAKE'] = 'true'
         self.assertEqual(make(parallel=True, output=str).strip(), '')
-        self.assertEqual(make('install', parallel=True, output=str).strip(), 'install')
+        self.assertEqual(make('install', parallel=True,
+                              output=str).strip(), 'install')
 
         os.environ['SPACK_NO_PARALLEL_MAKE'] = '1'
         self.assertEqual(make(parallel=True, output=str).strip(), '')
-        self.assertEqual(make('install', parallel=True, output=str).strip(), 'install')
+        self.assertEqual(make('install', parallel=True,
+                              output=str).strip(), 'install')
 
         # These don't disable (false and random string)
         os.environ['SPACK_NO_PARALLEL_MAKE'] = 'false'
         self.assertEqual(make(parallel=True, output=str).strip(), '-j8')
-        self.assertEqual(make('install', parallel=True, output=str).strip(), '-j8 install')
+        self.assertEqual(make('install', parallel=True,
+                              output=str).strip(), '-j8 install')
 
         os.environ['SPACK_NO_PARALLEL_MAKE'] = 'foobar'
         self.assertEqual(make(parallel=True, output=str).strip(), '-j8')
-        self.assertEqual(make('install', parallel=True, output=str).strip(), '-j8 install')
+        self.assertEqual(make('install', parallel=True,
+                              output=str).strip(), '-j8 install')
 
         del os.environ['SPACK_NO_PARALLEL_MAKE']
diff --git a/lib/spack/spack/test/mirror.py b/lib/spack/spack/test/mirror.py
index b682d4e097..d6d7b30b7c 100644
--- a/lib/spack/spack/test/mirror.py
+++ b/lib/spack/spack/test/mirror.py
@@ -35,6 +35,7 @@ exclude = ['.hg', '.git', '.svn']
 
 
 class MirrorTest(MockPackagesTest):
+
     def setUp(self):
         """Sets up a mock package and a mock repo for each fetch strategy, to
            ensure that the mirror can create archives for each of them.
@@ -42,7 +43,6 @@ class MirrorTest(MockPackagesTest):
         super(MirrorTest, self).setUp()
         self.repos = {}
 
-
     def tearDown(self):
         """Destroy all the stages created by the repos in setup."""
         super(MirrorTest, self).tearDown()
@@ -50,7 +50,6 @@ class MirrorTest(MockPackagesTest):
             repo.destroy()
         self.repos.clear()
 
-
     def set_up_package(self, name, MockRepoClass, url_attr):
         """Set up a mock package to be mirrored.
            Each package needs us to:
@@ -71,16 +70,14 @@ class MirrorTest(MockPackagesTest):
         v = next(iter(pkg.versions))
         pkg.versions[v][url_attr] = repo.url
 
-
     def check_mirror(self):
         with Stage('spack-mirror-test') as stage:
             mirror_root = join_path(stage.path, 'test-mirror')
 
             # register mirror with spack config
-            mirrors = { 'spack-mirror-test' : 'file://' + mirror_root }
+            mirrors = {'spack-mirror-test': 'file://' + mirror_root}
             spack.config.update_config('mirrors', mirrors)
 
-
             os.chdir(stage.path)
             spack.mirror.create(
                 mirror_root, self.repos, no_checksum=True)
@@ -110,16 +107,18 @@ class MirrorTest(MockPackagesTest):
                         original_path = mock_repo.path
                         if 'svn' in name:
                             # have to check out the svn repo to compare.
-                            original_path = join_path(mock_repo.path, 'checked_out')
+                            original_path = join_path(
+                                mock_repo.path, 'checked_out')
                             svn('checkout', mock_repo.url, original_path)
                         dcmp = dircmp(original_path, pkg.stage.source_path)
-                        # make sure there are no new files in the expanded tarball
+                        # make sure there are no new files in the expanded
+                        # tarball
                         self.assertFalse(dcmp.right_only)
                         # and that all original files are present.
-                        self.assertTrue(all(l in exclude for l in dcmp.left_only))
+                        self.assertTrue(
+                            all(l in exclude for l in dcmp.left_only))
                         spack.do_checksum = saved_checksum_setting
 
-
     def test_git_mirror(self):
         self.set_up_package('git-test', MockGitRepo, 'git')
         self.check_mirror()
diff --git a/lib/spack/spack/test/mock_database.py b/lib/spack/spack/test/mock_database.py
index da01e82bfa..d5867f06ec 100644
--- a/lib/spack/spack/test/mock_database.py
+++ b/lib/spack/spack/test/mock_database.py
@@ -33,6 +33,7 @@ from spack.test.mock_packages_test import MockPackagesTest
 
 
 class MockDatabase(MockPackagesTest):
+
     def _mock_install(self, spec):
         s = Spec(spec)
         s.concretize()
diff --git a/lib/spack/spack/test/mock_packages_test.py b/lib/spack/spack/test/mock_packages_test.py
index 9d96622a6e..82c2712b0e 100644
--- a/lib/spack/spack/test/mock_packages_test.py
+++ b/lib/spack/spack/test/mock_packages_test.py
@@ -155,7 +155,9 @@ packages:
       externalmodule@1.0%gcc@4.5.0: external-module
 """
 
+
 class MockPackagesTest(unittest.TestCase):
+
     def initmock(self):
         # Use the mock packages database for these tests.  This allows
         # us to set up contrived packages that don't interfere with
@@ -172,7 +174,8 @@ class MockPackagesTest(unittest.TestCase):
         self.mock_user_config = os.path.join(self.temp_config, 'user')
         mkdirp(self.mock_site_config)
         mkdirp(self.mock_user_config)
-        for confs in [('compilers.yaml', mock_compiler_config), ('packages.yaml', mock_packages_config)]:
+        for confs in [('compilers.yaml', mock_compiler_config),
+                      ('packages.yaml', mock_packages_config)]:
             conf_yaml = os.path.join(self.mock_site_config, confs[0])
             with open(conf_yaml, 'w') as f:
                 f.write(confs[1])
@@ -209,7 +212,6 @@ class MockPackagesTest(unittest.TestCase):
         pkg.dependencies[spec.name] = {Spec(pkg_name): spec}
         pkg._deptypes[spec.name] = set(deptypes)
 
-
     def cleanmock(self):
         """Restore the real packages path after any test."""
         spack.repo.swap(self.db)
@@ -226,10 +228,8 @@ class MockPackagesTest(unittest.TestCase):
         shutil.rmtree(spack.share_path, ignore_errors=True)
         spack.share_path = self.real_share_path
 
-
     def setUp(self):
         self.initmock()
 
-
     def tearDown(self):
         self.cleanmock()
diff --git a/lib/spack/spack/test/mock_repo.py b/lib/spack/spack/test/mock_repo.py
index 386af282e7..0ae7dbd516 100644
--- a/lib/spack/spack/test/mock_repo.py
+++ b/lib/spack/spack/test/mock_repo.py
@@ -40,6 +40,7 @@ tar      = which('tar',      required=True)
 
 
 class MockRepo(object):
+
     def __init__(self, stage_name, repo_name):
         """This creates a stage where some archive/repo files can be staged
            for testing spack's fetch strategies."""
@@ -50,7 +51,6 @@ class MockRepo(object):
         self.path = join_path(self.stage.path, repo_name)
         mkdirp(self.path)
 
-
     def destroy(self):
         """Destroy resources associated with this mock repo."""
         if self.stage:
@@ -90,6 +90,7 @@ class MockArchive(MockRepo):
 
 
 class MockVCSRepo(MockRepo):
+
     def __init__(self, stage_name, repo_name):
         """This creates a stage and a repo directory within the stage."""
         super(MockVCSRepo, self).__init__(stage_name, repo_name)
@@ -100,6 +101,7 @@ class MockVCSRepo(MockRepo):
 
 
 class MockGitRepo(MockVCSRepo):
+
     def __init__(self):
         super(MockGitRepo, self).__init__('mock-git-stage', 'mock-git-repo')
 
@@ -147,6 +149,7 @@ class MockGitRepo(MockVCSRepo):
 
 
 class MockSvnRepo(MockVCSRepo):
+
     def __init__(self):
         super(MockSvnRepo, self).__init__('mock-svn-stage', 'mock-svn-repo')
 
@@ -176,6 +179,7 @@ class MockSvnRepo(MockVCSRepo):
 
 
 class MockHgRepo(MockVCSRepo):
+
     def __init__(self):
         super(MockHgRepo, self).__init__('mock-hg-stage', 'mock-hg-repo')
         self.url = 'file://' + self.path
diff --git a/lib/spack/spack/test/multimethod.py b/lib/spack/spack/test/multimethod.py
index c233ea4fd6..a885374080 100644
--- a/lib/spack/spack/test/multimethod.py
+++ b/lib/spack/spack/test/multimethod.py
@@ -25,15 +25,10 @@
 """
 Test for multi_method dispatch.
 """
-import unittest
-
 import spack
 from spack.multimethod import *
 from spack.version import *
-from spack.spec import Spec
-from spack.multimethod import when
 from spack.test.mock_packages_test import *
-from spack.version import *
 
 
 class MultiMethodTest(MockPackagesTest):
@@ -42,7 +37,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod@2.0')
         self.assertRaises(NoSuchMethodError, pkg.no_version_2)
 
-
     def test_one_version_match(self):
         pkg = spack.repo.get('multimethod@1.0')
         self.assertEqual(pkg.no_version_2(), 1)
@@ -53,7 +47,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod@4.0')
         self.assertEqual(pkg.no_version_2(), 4)
 
-
     def test_version_overlap(self):
         pkg = spack.repo.get('multimethod@2.0')
         self.assertEqual(pkg.version_overlap(), 1)
@@ -61,7 +54,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod@5.0')
         self.assertEqual(pkg.version_overlap(), 2)
 
-
     def test_mpi_version(self):
         pkg = spack.repo.get('multimethod^mpich@3.0.4')
         self.assertEqual(pkg.mpi_version(), 3)
@@ -72,7 +64,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod^mpich@1.0')
         self.assertEqual(pkg.mpi_version(), 1)
 
-
     def test_undefined_mpi_version(self):
         pkg = spack.repo.get('multimethod^mpich@0.4')
         self.assertEqual(pkg.mpi_version(), 1)
@@ -80,7 +71,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod^mpich@1.4')
         self.assertEqual(pkg.mpi_version(), 1)
 
-
     def test_default_works(self):
         pkg = spack.repo.get('multimethod%gcc')
         self.assertEqual(pkg.has_a_default(), 'gcc')
@@ -91,21 +81,19 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod%pgi')
         self.assertEqual(pkg.has_a_default(), 'default')
 
-
     def test_target_match(self):
         platform = spack.architecture.platform()
         targets = platform.targets.values()
         for target in targets[:-1]:
-            pkg = spack.repo.get('multimethod target='+target.name)
+            pkg = spack.repo.get('multimethod target=' + target.name)
             self.assertEqual(pkg.different_by_target(), target.name)
 
-        pkg = spack.repo.get('multimethod target='+targets[-1].name)
+        pkg = spack.repo.get('multimethod target=' + targets[-1].name)
         if len(targets) == 1:
             self.assertEqual(pkg.different_by_target(), targets[-1].name)
         else:
             self.assertRaises(NoSuchMethodError, pkg.different_by_target)
 
-
     def test_dependency_match(self):
         pkg = spack.repo.get('multimethod^zmpi')
         self.assertEqual(pkg.different_by_dep(), 'zmpi')
@@ -118,7 +106,6 @@ class MultiMethodTest(MockPackagesTest):
         pkg = spack.repo.get('multimethod^foobar')
         self.assertEqual(pkg.different_by_dep(), 'mpich')
 
-
     def test_virtual_dep_match(self):
         pkg = spack.repo.get('multimethod^mpich2')
         self.assertEqual(pkg.different_by_virtual_dep(), 2)
diff --git a/lib/spack/spack/test/namespace_trie.py b/lib/spack/spack/test/namespace_trie.py
index b38ecd6179..7927fc8e60 100644
--- a/lib/spack/spack/test/namespace_trie.py
+++ b/lib/spack/spack/test/namespace_trie.py
@@ -32,7 +32,6 @@ class NamespaceTrieTest(unittest.TestCase):
     def setUp(self):
         self.trie = NamespaceTrie()
 
-
     def test_add_single(self):
         self.trie['foo'] = 'bar'
 
@@ -40,7 +39,6 @@ class NamespaceTrieTest(unittest.TestCase):
         self.assertTrue(self.trie.has_value('foo'))
         self.assertEqual(self.trie['foo'], 'bar')
 
-
     def test_add_multiple(self):
         self.trie['foo.bar'] = 'baz'
 
@@ -54,7 +52,6 @@ class NamespaceTrieTest(unittest.TestCase):
         self.assertFalse(self.trie.is_prefix('foo.bar.baz'))
         self.assertFalse(self.trie.has_value('foo.bar.baz'))
 
-
     def test_add_three(self):
         # add a three-level namespace
         self.trie['foo.bar.baz'] = 'quux'
@@ -89,7 +86,6 @@ class NamespaceTrieTest(unittest.TestCase):
         self.assertFalse(self.trie.is_prefix('foo.bar.baz.quux'))
         self.assertFalse(self.trie.has_value('foo.bar.baz.quux'))
 
-
     def test_add_none_single(self):
         self.trie['foo'] = None
         self.assertTrue(self.trie.is_prefix('foo'))
@@ -99,8 +95,6 @@ class NamespaceTrieTest(unittest.TestCase):
         self.assertFalse(self.trie.is_prefix('foo.bar'))
         self.assertFalse(self.trie.has_value('foo.bar'))
 
-
-
     def test_add_none_multiple(self):
         self.trie['foo.bar'] = None
 
diff --git a/lib/spack/spack/test/operating_system.py b/lib/spack/spack/test/operating_system.py
index ed5f6ff8ad..8723f7244d 100644
--- a/lib/spack/spack/test/operating_system.py
+++ b/lib/spack/spack/test/operating_system.py
@@ -1,18 +1,39 @@
+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
 """ Test checks if the operating_system class is created correctly and that
 the functions are using the correct operating_system. Also checks whether
 the operating_system correctly uses the compiler_strategy
 """
-
 import unittest
-import os
-import platform
 from spack.platforms.cray_xc import CrayXc
 from spack.platforms.linux import Linux
 from spack.platforms.darwin import Darwin
 from spack.operating_system.linux_distro import LinuxDistro
-from spack.operating_system.mac_os import MacOs
 from spack.operating_system.cnl import ComputeNodeLinux
 
+
 class TestOperatingSystem(unittest.TestCase):
 
     def setUp(self):
@@ -32,7 +53,7 @@ class TestOperatingSystem(unittest.TestCase):
         self.assertEquals(self.cray_operating_sys.compiler_strategy, "PATH")
 
     def test_cray_back_end_operating_system(self):
-        self.assertIsInstance(self.cray_back_os,ComputeNodeLinux)
+        self.assertIsInstance(self.cray_back_os, ComputeNodeLinux)
 
     def test_cray_back_end_compiler_strategy(self):
         self.assertEquals(self.cray_back_os.compiler_strategy, "MODULES")
@@ -43,7 +64,6 @@ class TestOperatingSystem(unittest.TestCase):
     def test_linux_compiler_strategy(self):
         self.assertEquals(self.linux_operating_sys.compiler_strategy, "PATH")
 
-
     def test_cray_front_end_compiler_list(self):
         """ Operating systems will now be in charge of finding compilers.
             So, depending on which operating system you want to build for
diff --git a/lib/spack/spack/test/optional_deps.py b/lib/spack/spack/test/optional_deps.py
index b5ba0ecf35..a9a2b9abf5 100644
--- a/lib/spack/spack/test/optional_deps.py
+++ b/lib/spack/spack/test/optional_deps.py
@@ -22,10 +22,10 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-
 from spack.spec import Spec
 from spack.test.mock_packages_test import *
 
+
 class ConcretizeTest(MockPackagesTest):
 
     def check_normalize(self, spec_string, expected):
@@ -34,10 +34,10 @@ class ConcretizeTest(MockPackagesTest):
         self.assertEqual(spec, expected)
         self.assertTrue(spec.eq_dag(expected))
 
-
     def test_normalize_simple_conditionals(self):
         self.check_normalize('optional-dep-test', Spec('optional-dep-test'))
-        self.check_normalize('optional-dep-test~a', Spec('optional-dep-test~a'))
+        self.check_normalize('optional-dep-test~a',
+                             Spec('optional-dep-test~a'))
 
         self.check_normalize('optional-dep-test+a',
                              Spec('optional-dep-test+a', Spec('a')))
@@ -45,7 +45,6 @@ class ConcretizeTest(MockPackagesTest):
         self.check_normalize('optional-dep-test a=true',
                              Spec('optional-dep-test a=true', Spec('a')))
 
-
         self.check_normalize('optional-dep-test a=true',
                              Spec('optional-dep-test+a', Spec('a')))
 
@@ -55,25 +54,29 @@ class ConcretizeTest(MockPackagesTest):
         self.check_normalize('optional-dep-test%intel',
                              Spec('optional-dep-test%intel', Spec('c')))
 
-        self.check_normalize('optional-dep-test%intel@64.1',
-                             Spec('optional-dep-test%intel@64.1', Spec('c'), Spec('d')))
+        self.check_normalize(
+            'optional-dep-test%intel@64.1',
+            Spec('optional-dep-test%intel@64.1', Spec('c'), Spec('d')))
 
-        self.check_normalize('optional-dep-test%intel@64.1.2',
-                             Spec('optional-dep-test%intel@64.1.2', Spec('c'), Spec('d')))
+        self.check_normalize(
+            'optional-dep-test%intel@64.1.2',
+            Spec('optional-dep-test%intel@64.1.2', Spec('c'), Spec('d')))
 
         self.check_normalize('optional-dep-test%clang@35',
                              Spec('optional-dep-test%clang@35', Spec('e')))
 
-
     def test_multiple_conditionals(self):
-        self.check_normalize('optional-dep-test+a@1.1',
-                             Spec('optional-dep-test+a@1.1', Spec('a'), Spec('b')))
+        self.check_normalize(
+            'optional-dep-test+a@1.1',
+            Spec('optional-dep-test+a@1.1', Spec('a'), Spec('b')))
 
-        self.check_normalize('optional-dep-test+a%intel',
-                             Spec('optional-dep-test+a%intel', Spec('a'), Spec('c')))
+        self.check_normalize(
+            'optional-dep-test+a%intel',
+            Spec('optional-dep-test+a%intel', Spec('a'), Spec('c')))
 
-        self.check_normalize('optional-dep-test@1.1%intel',
-                             Spec('optional-dep-test@1.1%intel', Spec('b'), Spec('c')))
+        self.check_normalize(
+            'optional-dep-test@1.1%intel',
+            Spec('optional-dep-test@1.1%intel', Spec('b'), Spec('c')))
 
         self.check_normalize('optional-dep-test@1.1%intel@64.1.2+a',
                              Spec('optional-dep-test@1.1%intel@64.1.2+a',
@@ -83,14 +86,12 @@ class ConcretizeTest(MockPackagesTest):
                              Spec('optional-dep-test@1.1%clang@36.5+a',
                                   Spec('b'), Spec('a'), Spec('e')))
 
-
     def test_chained_mpi(self):
         self.check_normalize('optional-dep-test-2+mpi',
                              Spec('optional-dep-test-2+mpi',
                                   Spec('optional-dep-test+mpi',
                                        Spec('mpi'))))
 
-
     def test_default_variant(self):
         spec = Spec('optional-dep-test-3')
         spec.concretize()
@@ -104,7 +105,6 @@ class ConcretizeTest(MockPackagesTest):
         spec.concretize()
         self.assertTrue('b' in spec)
 
-
     def test_transitive_chain(self):
         # Each of these dependencies comes from a conditional
         # dependency on another.  This requires iterating to evaluate
diff --git a/lib/spack/spack/test/package_sanity.py b/lib/spack/spack/test/package_sanity.py
index 9198986f5d..c3c3923855 100644
--- a/lib/spack/spack/test/package_sanity.py
+++ b/lib/spack/spack/test/package_sanity.py
@@ -38,12 +38,10 @@ class PackageSanityTest(unittest.TestCase):
         for name in spack.repo.all_package_names():
             spack.repo.get(name)
 
-
     def test_get_all_packages(self):
         """Get all packages once and make sure that works."""
         self.check_db()
 
-
     def test_get_all_mock_packages(self):
         """Get the mock packages once each too."""
         db = RepoPath(spack.mock_packages_path)
@@ -51,7 +49,6 @@ class PackageSanityTest(unittest.TestCase):
         self.check_db()
         spack.repo.swap(db)
 
-
     def test_url_versions(self):
         """Check URLs for regular packages, if they are explicitly defined."""
         for pkg in spack.repo.all_packages():
diff --git a/lib/spack/spack/test/packages.py b/lib/spack/spack/test/packages.py
index bea42bb33a..fdd079a8f7 100644
--- a/lib/spack/spack/test/packages.py
+++ b/lib/spack/spack/test/packages.py
@@ -22,7 +22,6 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-
 import spack
 from llnl.util.filesystem import join_path
 from spack.repository import Repo
@@ -33,33 +32,26 @@ from spack.util.naming import mod_to_class
 class PackagesTest(MockPackagesTest):
 
     def test_load_package(self):
-        pkg = spack.repo.get('mpich')
-
+        spack.repo.get('mpich')
 
     def test_package_name(self):
         pkg = spack.repo.get('mpich')
         self.assertEqual(pkg.name, 'mpich')
 
-
     def test_package_filename(self):
         repo = Repo(spack.mock_packages_path)
         filename = repo.filename_for_package_name('mpich')
         self.assertEqual(filename,
-                         join_path(spack.mock_packages_path, 'packages', 'mpich', 'package.py'))
-
-
-    def test_package_name(self):
-        pkg = spack.repo.get('mpich')
-        self.assertEqual(pkg.name, 'mpich')
-
+                         join_path(spack.mock_packages_path,
+                                   'packages', 'mpich', 'package.py'))
 
     def test_nonexisting_package_filename(self):
         repo = Repo(spack.mock_packages_path)
         filename = repo.filename_for_package_name('some-nonexisting-package')
         self.assertEqual(
             filename,
-            join_path(spack.mock_packages_path, 'packages', 'some-nonexisting-package', 'package.py'))
-
+            join_path(spack.mock_packages_path,
+                      'packages', 'some-nonexisting-package', 'package.py'))
 
     def test_package_class_names(self):
         self.assertEqual('Mpich',          mod_to_class('mpich'))
@@ -68,37 +60,32 @@ class PackagesTest(MockPackagesTest):
         self.assertEqual('Pmgrcollective', mod_to_class('PmgrCollective'))
         self.assertEqual('_3db',        mod_to_class('3db'))
 
-
     #
     # Below tests target direct imports of spack packages from the
     # spack.pkg namespace
     #
 
     def test_import_package(self):
-        import spack.pkg.builtin.mock.mpich
-
+        import spack.pkg.builtin.mock.mpich             # noqa
 
     def test_import_package_as(self):
-        import spack.pkg.builtin.mock.mpich as mp
-
+        import spack.pkg.builtin.mock.mpich as mp       # noqa
 
     def test_import_class_from_package(self):
-        from spack.pkg.builtin.mock.mpich import Mpich
-
+        from spack.pkg.builtin.mock.mpich import Mpich  # noqa
 
     def test_import_module_from_package(self):
-        from spack.pkg.builtin.mock import mpich
-
+        from spack.pkg.builtin.mock import mpich        # noqa
 
     def test_import_namespace_container_modules(self):
-        import spack.pkg
-        import spack.pkg as p
-        from spack import pkg
+        import spack.pkg                                # noqa
+        import spack.pkg as p                           # noqa
+        from spack import pkg                           # noqa
 
-        import spack.pkg.builtin
-        import spack.pkg.builtin as b
-        from spack.pkg import builtin
+        import spack.pkg.builtin                        # noqa
+        import spack.pkg.builtin as b                   # noqa
+        from spack.pkg import builtin                   # noqa
 
-        import spack.pkg.builtin.mock
-        import spack.pkg.builtin.mock as m
-        from spack.pkg.builtin import mock
+        import spack.pkg.builtin.mock                   # noqa
+        import spack.pkg.builtin.mock as m              # noqa
+        from spack.pkg.builtin import mock              # noqa
diff --git a/lib/spack/spack/test/pattern.py b/lib/spack/spack/test/pattern.py
index 3419d600b8..0c772a0d2d 100644
--- a/lib/spack/spack/test/pattern.py
+++ b/lib/spack/spack/test/pattern.py
@@ -41,6 +41,7 @@ class CompositeTest(unittest.TestCase):
                 raise NotImplemented('subtract not implemented')
 
         class One(Base):
+
             def add(self):
                 Base.counter += 1
 
@@ -48,6 +49,7 @@ class CompositeTest(unittest.TestCase):
                 Base.counter -= 1
 
         class Two(Base):
+
             def add(self):
                 Base.counter += 2
 
diff --git a/lib/spack/spack/test/python_version.py b/lib/spack/spack/test/python_version.py
index 6c09effc56..5af55bdc5f 100644
--- a/lib/spack/spack/test/python_version.py
+++ b/lib/spack/spack/test/python_version.py
@@ -36,7 +36,8 @@ import llnl.util.tty as tty
 import pyqver2
 import spack
 
-spack_max_version = (2,6)
+spack_max_version = (2, 6)
+
 
 class PythonVersionTest(unittest.TestCase):
 
@@ -51,12 +52,10 @@ class PythonVersionTest(unittest.TestCase):
                     if re.match(r'^[^.#].*\.py$', filename):
                         yield os.path.join(root, filename)
 
-
     def package_py_files(self):
         for name in spack.repo.all_package_names():
             yield spack.repo.filename_for_package_name(name)
 
-
     def check_python_versions(self, *files):
         # dict version -> filename -> reasons
         all_issues = {}
@@ -66,7 +65,7 @@ class PythonVersionTest(unittest.TestCase):
                 versions = pyqver2.get_versions(pyfile.read())
                 for ver, reasons in versions.items():
                     if ver > spack_max_version:
-                        if not ver in all_issues:
+                        if ver not in all_issues:
                             all_issues[ver] = {}
                         all_issues[ver][fn] = reasons
 
@@ -87,7 +86,7 @@ class PythonVersionTest(unittest.TestCase):
 
             tty.error("These files require version %d.%d:" % v)
             maxlen = max(len(f) for f, prob in msgs)
-            fmt = "%%-%ds%%s" % (maxlen+3)
+            fmt = "%%-%ds%%s" % (maxlen + 3)
             print fmt % ('File', 'Reason')
             print fmt % ('-' * (maxlen), '-' * 20)
             for msg in msgs:
@@ -95,10 +94,8 @@ class PythonVersionTest(unittest.TestCase):
 
         self.assertTrue(len(all_issues) == 0)
 
-
     def test_core_module_compatibility(self):
         self.check_python_versions(*self.pyfiles(spack.lib_path))
 
-
     def test_package_module_compatibility(self):
         self.check_python_versions(*self.pyfiles(spack.packages_path))
diff --git a/lib/spack/spack/test/sbang.py b/lib/spack/spack/test/sbang.py
index 4ce854a1d8..12abce7b35 100644
--- a/lib/spack/spack/test/sbang.py
+++ b/lib/spack/spack/test/sbang.py
@@ -44,6 +44,7 @@ last_line        = "last!\n"
 
 
 class SbangTest(unittest.TestCase):
+
     def setUp(self):
         self.tempdir = tempfile.mkdtemp()
 
diff --git a/lib/spack/spack/test/spec_dag.py b/lib/spack/spack/test/spec_dag.py
index 8522431fbb..8f61c7ac76 100644
--- a/lib/spack/spack/test/spec_dag.py
+++ b/lib/spack/spack/test/spec_dag.py
@@ -455,6 +455,7 @@ class SpecDagTest(MockPackagesTest):
 
         run3 -b-> build3
     """
+
     def test_deptype_traversal(self):
         dag = Spec('dtuse')
         dag.normalize()
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index b174e5305c..79ffc99298 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -22,18 +22,18 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
-import unittest
 import spack.architecture
 from spack.spec import *
 from spack.test.mock_packages_test import *
 
+
 class SpecSematicsTest(MockPackagesTest):
     """This tests satisfies(), constrain() and other semantic operations
        on specs."""
 
-    # ================================================================================
+    # ========================================================================
     # Utility functions to set everything up.
-    # ================================================================================
+    # ========================================================================
     def check_satisfies(self, spec, anon_spec, concrete=False):
         left = Spec(spec, concrete=concrete)
         try:
@@ -49,7 +49,6 @@ class SpecSematicsTest(MockPackagesTest):
         # right by left.  Reverse is not always true.
         right.copy().constrain(left)
 
-
     def check_unsatisfiable(self, spec, anon_spec, concrete=False):
         left = Spec(spec, concrete=concrete)
         try:
@@ -62,7 +61,6 @@ class SpecSematicsTest(MockPackagesTest):
 
         self.assertRaises(UnsatisfiableSpecError, right.copy().constrain, left)
 
-
     def check_constrain(self, expected, spec, constraint):
         exp = Spec(expected)
         spec = Spec(spec)
@@ -70,53 +68,48 @@ class SpecSematicsTest(MockPackagesTest):
         spec.constrain(constraint)
         self.assertEqual(exp, spec)
 
-
     def check_constrain_changed(self, spec, constraint):
         spec = Spec(spec)
         self.assertTrue(spec.constrain(constraint))
 
-
     def check_constrain_not_changed(self, spec, constraint):
         spec = Spec(spec)
         self.assertFalse(spec.constrain(constraint))
 
-
     def check_invalid_constraint(self, spec, constraint):
         spec = Spec(spec)
         constraint = Spec(constraint)
         self.assertRaises(UnsatisfiableSpecError, spec.constrain, constraint)
 
-
-    # ================================================================================
+    # ========================================================================
     # Satisfiability
-    # ================================================================================
+    # ========================================================================
     def test_satisfies(self):
         self.check_satisfies('libelf@0.8.13', '@0:1')
         self.check_satisfies('libdwarf^libelf@0.8.13', '^libelf@0:1')
 
-
     def test_satisfies_namespace(self):
         self.check_satisfies('builtin.mpich', 'mpich')
         self.check_satisfies('builtin.mock.mpich', 'mpich')
 
-        # TODO: only works for deps now, but shouldn't we allow this for root spec?
+        # TODO: only works for deps now, but shouldn't we allow for root spec?
         # self.check_satisfies('builtin.mock.mpich', 'mpi')
 
         self.check_satisfies('builtin.mock.mpich', 'builtin.mock.mpich')
 
         self.check_unsatisfiable('builtin.mock.mpich', 'builtin.mpich')
 
-
     def test_satisfies_namespaced_dep(self):
         """Ensure spec from same or unspecified namespace satisfies namespace
            constraint."""
         self.check_satisfies('mpileaks ^builtin.mock.mpich', '^mpich')
 
         self.check_satisfies('mpileaks ^builtin.mock.mpich', '^mpi')
-        self.check_satisfies('mpileaks ^builtin.mock.mpich', '^builtin.mock.mpich')
-
-        self.check_unsatisfiable('mpileaks ^builtin.mock.mpich', '^builtin.mpich')
+        self.check_satisfies(
+            'mpileaks ^builtin.mock.mpich', '^builtin.mock.mpich')
 
+        self.check_unsatisfiable(
+            'mpileaks ^builtin.mock.mpich', '^builtin.mpich')
 
     def test_satisfies_compiler(self):
         self.check_satisfies('foo%gcc', '%gcc')
@@ -124,7 +117,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_unsatisfiable('foo%intel', '%gcc')
         self.check_unsatisfiable('foo%intel', '%pgi')
 
-
     def test_satisfies_compiler_version(self):
         self.check_satisfies('foo%gcc', '%gcc@4.7.2')
         self.check_satisfies('foo%intel', '%intel@4.7.2')
@@ -139,7 +131,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_satisfies('foo %gcc@4.7.3', '%gcc@4.7')
         self.check_unsatisfiable('foo %gcc@4.7', '%gcc@4.7.3')
 
-
     def test_satisfies_architecture(self):
         self.check_satisfies(
             'foo platform=test target=frontend os=frontend',
@@ -151,7 +142,6 @@ class SpecSematicsTest(MockPackagesTest):
             'foo platform=test target=default_target os=default_os',
             'platform=test target=default_target os=default_os')
 
-
     def test_satisfies_dependencies(self):
         self.check_satisfies('mpileaks^mpich', '^mpich')
         self.check_satisfies('mpileaks^zmpi', '^zmpi')
@@ -159,7 +149,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_unsatisfiable('mpileaks^mpich', '^zmpi')
         self.check_unsatisfiable('mpileaks^zmpi', '^mpich')
 
-
     def test_satisfies_dependency_versions(self):
         self.check_satisfies('mpileaks^mpich@2.0', '^mpich@1:3')
         self.check_unsatisfiable('mpileaks^mpich@1.2', '^mpich@2.0')
@@ -173,7 +162,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_unsatisfiable(
             'mpileaks^mpich@4.0^callpath@1.7', '^mpich@1:3^callpath@1.4:1.6')
 
-
     def test_satisfies_virtual_dependencies(self):
         self.check_satisfies('mpileaks^mpi', '^mpi')
         self.check_satisfies('mpileaks^mpi', '^mpich')
@@ -181,7 +169,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_satisfies('mpileaks^mpi', '^zmpi')
         self.check_unsatisfiable('mpileaks^mpich', '^zmpi')
 
-
     def test_satisfies_virtual_dependency_versions(self):
         self.check_satisfies('mpileaks^mpi@1.5', '^mpi@1.2:1.6')
         self.check_unsatisfiable('mpileaks^mpi@3', '^mpi@1.2:1.6')
@@ -197,26 +184,23 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_unsatisfiable('mpileaks^mpi@3:', '^mpich2')
         self.check_unsatisfiable('mpileaks^mpi@3:', '^mpich@1.0')
 
-
     def test_satisfies_matching_variant(self):
         self.check_satisfies('mpich+foo', 'mpich+foo')
         self.check_satisfies('mpich~foo', 'mpich~foo')
         self.check_satisfies('mpich foo=1', 'mpich foo=1')
 
-        #confirm that synonymous syntax works correctly
+        # confirm that synonymous syntax works correctly
         self.check_satisfies('mpich+foo', 'mpich foo=True')
         self.check_satisfies('mpich foo=true', 'mpich+foo')
         self.check_satisfies('mpich~foo', 'mpich foo=FALSE')
         self.check_satisfies('mpich foo=False', 'mpich~foo')
 
-
     def test_satisfies_unconstrained_variant(self):
         # only asked for mpich, no constraints.  Either will do.
         self.check_satisfies('mpich+foo', 'mpich')
         self.check_satisfies('mpich~foo', 'mpich')
         self.check_satisfies('mpich foo=1', 'mpich')
 
-
     def test_unsatisfiable_variants(self):
         # This case is different depending on whether the specs are concrete.
 
@@ -230,24 +214,21 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_unsatisfiable('mpich', 'mpich~foo', True)
         self.check_unsatisfiable('mpich', 'mpich foo=1', True)
 
-
     def test_unsatisfiable_variant_mismatch(self):
         # No matchi in specs
         self.check_unsatisfiable('mpich~foo', 'mpich+foo')
         self.check_unsatisfiable('mpich+foo', 'mpich~foo')
         self.check_unsatisfiable('mpich foo=1', 'mpich foo=2')
 
-
     def test_satisfies_matching_compiler_flag(self):
         self.check_satisfies('mpich cppflags="-O3"', 'mpich cppflags="-O3"')
-        self.check_satisfies('mpich cppflags="-O3 -Wall"', 'mpich cppflags="-O3 -Wall"')
-
+        self.check_satisfies('mpich cppflags="-O3 -Wall"',
+                             'mpich cppflags="-O3 -Wall"')
 
     def test_satisfies_unconstrained_compiler_flag(self):
         # only asked for mpich, no constraints.  Any will do.
         self.check_satisfies('mpich cppflags="-O3"', 'mpich')
 
-
     def test_unsatisfiable_compiler_flag(self):
         # This case is different depending on whether the specs are concrete.
 
@@ -257,11 +238,10 @@ class SpecSematicsTest(MockPackagesTest):
         # 'mpich' is concrete:
         self.check_unsatisfiable('mpich', 'mpich cppflags="-O3"', True)
 
-
     def test_unsatisfiable_compiler_flag_mismatch(self):
         # No matchi in specs
-        self.check_unsatisfiable('mpich cppflags="-O3"', 'mpich cppflags="-O2"')
-
+        self.check_unsatisfiable(
+            'mpich cppflags="-O3"', 'mpich cppflags="-O2"')
 
     def test_satisfies_virtual(self):
         # Don't use check_satisfies: it checks constrain() too, and
@@ -270,25 +250,30 @@ class SpecSematicsTest(MockPackagesTest):
         self.assertTrue(Spec('mpich2').satisfies(Spec('mpi')))
         self.assertTrue(Spec('zmpi').satisfies(Spec('mpi')))
 
-
     def test_satisfies_virtual_dep_with_virtual_constraint(self):
         """Ensure we can satisfy virtual constraints when there are multiple
            vdep providers in the specs."""
-        self.assertTrue(Spec('netlib-lapack ^openblas').satisfies('netlib-lapack ^openblas'))
-        self.assertFalse(Spec('netlib-lapack ^netlib-blas').satisfies('netlib-lapack ^openblas'))
-
-        self.assertFalse(Spec('netlib-lapack ^openblas').satisfies('netlib-lapack ^netlib-blas'))
-        self.assertTrue(Spec('netlib-lapack ^netlib-blas').satisfies('netlib-lapack ^netlib-blas'))
-
-
-    # ================================================================================
+        self.assertTrue(
+            Spec('netlib-lapack ^openblas').satisfies(
+                'netlib-lapack ^openblas'))
+        self.assertFalse(
+            Spec('netlib-lapack ^netlib-blas').satisfies(
+                'netlib-lapack ^openblas'))
+
+        self.assertFalse(
+            Spec('netlib-lapack ^openblas').satisfies(
+                'netlib-lapack ^netlib-blas'))
+        self.assertTrue(
+            Spec('netlib-lapack ^netlib-blas').satisfies(
+                'netlib-lapack ^netlib-blas'))
+
+    # ========================================================================
     # Indexing specs
-    # ================================================================================
+    # ========================================================================
     def test_self_index(self):
         s = Spec('callpath')
         self.assertTrue(s['callpath'] == s)
 
-
     def test_dep_index(self):
         s = Spec('callpath')
         s.normalize()
@@ -304,7 +289,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.assertTrue(s['libelf'].name   == 'libelf')
         self.assertTrue(s['mpi'].name      == 'mpi')
 
-
     def test_spec_contains_deps(self):
         s = Spec('callpath')
         s.normalize()
@@ -313,7 +297,6 @@ class SpecSematicsTest(MockPackagesTest):
         self.assertTrue('libelf' in s)
         self.assertTrue('mpi' in s)
 
-
     def test_virtual_index(self):
         s = Spec('callpath')
         s.concretize()
@@ -327,7 +310,6 @@ class SpecSematicsTest(MockPackagesTest):
         s_zmpi = Spec('callpath ^zmpi')
         s_zmpi.concretize()
 
-
         self.assertTrue(s['mpi'].name != 'mpi')
         self.assertTrue(s_mpich['mpi'].name == 'mpich')
         self.assertTrue(s_mpich2['mpi'].name == 'mpich2')
@@ -336,29 +318,34 @@ class SpecSematicsTest(MockPackagesTest):
         for spec in [s, s_mpich, s_mpich2, s_zmpi]:
             self.assertTrue('mpi' in spec)
 
-
-    # ================================================================================
+    # ========================================================================
     # Constraints
-    # ================================================================================
+    # ========================================================================
     def test_constrain_variants(self):
         self.check_constrain('libelf@2.1:2.5', 'libelf@0:2.5', 'libelf@2.1:3')
         self.check_constrain('libelf@2.1:2.5%gcc@4.5:4.6',
-                             'libelf@0:2.5%gcc@2:4.6', 'libelf@2.1:3%gcc@4.5:4.7')
+                             'libelf@0:2.5%gcc@2:4.6',
+                             'libelf@2.1:3%gcc@4.5:4.7')
 
         self.check_constrain('libelf+debug+foo', 'libelf+debug', 'libelf+foo')
-        self.check_constrain('libelf+debug+foo', 'libelf+debug', 'libelf+debug+foo')
+        self.check_constrain('libelf+debug+foo',
+                             'libelf+debug', 'libelf+debug+foo')
 
-        self.check_constrain('libelf debug=2 foo=1', 'libelf debug=2', 'libelf foo=1')
-        self.check_constrain('libelf debug=2 foo=1', 'libelf debug=2', 'libelf debug=2 foo=1')
+        self.check_constrain('libelf debug=2 foo=1',
+                             'libelf debug=2', 'libelf foo=1')
+        self.check_constrain('libelf debug=2 foo=1',
+                             'libelf debug=2', 'libelf debug=2 foo=1')
 
         self.check_constrain('libelf+debug~foo', 'libelf+debug', 'libelf~foo')
-        self.check_constrain('libelf+debug~foo', 'libelf+debug', 'libelf+debug~foo')
-
+        self.check_constrain('libelf+debug~foo',
+                             'libelf+debug', 'libelf+debug~foo')
 
     def test_constrain_compiler_flags(self):
-        self.check_constrain('libelf cflags="-O3" cppflags="-Wall"', 'libelf cflags="-O3"', 'libelf cppflags="-Wall"')
-        self.check_constrain('libelf cflags="-O3" cppflags="-Wall"', 'libelf cflags="-O3"', 'libelf cflags="-O3" cppflags="-Wall"')
-
+        self.check_constrain('libelf cflags="-O3" cppflags="-Wall"',
+                             'libelf cflags="-O3"', 'libelf cppflags="-Wall"')
+        self.check_constrain('libelf cflags="-O3" cppflags="-Wall"',
+                             'libelf cflags="-O3"',
+                             'libelf cflags="-O3" cppflags="-Wall"')
 
     def test_constrain_architecture(self):
         self.check_constrain('libelf target=default_target os=default_os',
@@ -369,21 +356,24 @@ class SpecSematicsTest(MockPackagesTest):
                              'libelf target=default_target os=default_os')
 
     def test_constrain_compiler(self):
-        self.check_constrain('libelf %gcc@4.4.7', 'libelf %gcc@4.4.7', 'libelf %gcc@4.4.7')
-        self.check_constrain('libelf %gcc@4.4.7', 'libelf', 'libelf %gcc@4.4.7')
-
+        self.check_constrain('libelf %gcc@4.4.7',
+                             'libelf %gcc@4.4.7', 'libelf %gcc@4.4.7')
+        self.check_constrain('libelf %gcc@4.4.7',
+                             'libelf', 'libelf %gcc@4.4.7')
 
     def test_invalid_constraint(self):
         self.check_invalid_constraint('libelf@0:2.0', 'libelf@2.1:3')
-        self.check_invalid_constraint('libelf@0:2.5%gcc@4.8:4.9', 'libelf@2.1:3%gcc@4.5:4.7')
+        self.check_invalid_constraint(
+            'libelf@0:2.5%gcc@4.8:4.9', 'libelf@2.1:3%gcc@4.5:4.7')
 
         self.check_invalid_constraint('libelf+debug', 'libelf~debug')
         self.check_invalid_constraint('libelf+debug~foo', 'libelf+debug+foo')
         self.check_invalid_constraint('libelf debug=2', 'libelf debug=1')
 
-        self.check_invalid_constraint('libelf cppflags="-O3"', 'libelf cppflags="-O2"')
+        self.check_invalid_constraint(
+            'libelf cppflags="-O3"', 'libelf cppflags="-O2"')
         self.check_invalid_constraint('libelf platform=test target=be os=be',
-                                          'libelf target=fe os=fe')
+                                      'libelf target=fe os=fe')
 
     def test_constrain_changed(self):
         self.check_constrain_changed('libelf', '@1.0')
@@ -396,9 +386,10 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_constrain_changed('libelf', 'cppflags="-O3"')
 
         platform = spack.architecture.platform()
-        self.check_constrain_changed('libelf', 'target='+platform.target('default_target').name)
-        self.check_constrain_changed('libelf', 'os='+platform.operating_system('default_os').name)
-
+        self.check_constrain_changed(
+            'libelf', 'target=' + platform.target('default_target').name)
+        self.check_constrain_changed(
+            'libelf', 'os=' + platform.operating_system('default_os').name)
 
     def test_constrain_not_changed(self):
         self.check_constrain_not_changed('libelf', 'libelf')
@@ -409,12 +400,13 @@ class SpecSematicsTest(MockPackagesTest):
         self.check_constrain_not_changed('libelf+debug', '+debug')
         self.check_constrain_not_changed('libelf~debug', '~debug')
         self.check_constrain_not_changed('libelf debug=2', 'debug=2')
-        self.check_constrain_not_changed('libelf cppflags="-O3"', 'cppflags="-O3"')
+        self.check_constrain_not_changed(
+            'libelf cppflags="-O3"', 'cppflags="-O3"')
 
         platform = spack.architecture.platform()
         default_target = platform.target('default_target').name
-        self.check_constrain_not_changed('libelf target='+default_target, 'target='+default_target)
-
+        self.check_constrain_not_changed(
+            'libelf target=' + default_target, 'target=' + default_target)
 
     def test_constrain_dependency_changed(self):
         self.check_constrain_changed('libelf^foo', 'libelf^foo@1.0')
@@ -426,18 +418,25 @@ class SpecSematicsTest(MockPackagesTest):
 
         platform = spack.architecture.platform()
         default_target = platform.target('default_target').name
-        self.check_constrain_changed('libelf^foo', 'libelf^foo target='+default_target)
-
+        self.check_constrain_changed(
+            'libelf^foo', 'libelf^foo target=' + default_target)
 
     def test_constrain_dependency_not_changed(self):
         self.check_constrain_not_changed('libelf^foo@1.0', 'libelf^foo@1.0')
-        self.check_constrain_not_changed('libelf^foo@1.0:5.0', 'libelf^foo@1.0:5.0')
+        self.check_constrain_not_changed(
+            'libelf^foo@1.0:5.0', 'libelf^foo@1.0:5.0')
         self.check_constrain_not_changed('libelf^foo%gcc', 'libelf^foo%gcc')
-        self.check_constrain_not_changed('libelf^foo%gcc@4.5', 'libelf^foo%gcc@4.5')
-        self.check_constrain_not_changed('libelf^foo+debug', 'libelf^foo+debug')
-        self.check_constrain_not_changed('libelf^foo~debug', 'libelf^foo~debug')
-        self.check_constrain_not_changed('libelf^foo cppflags="-O3"', 'libelf^foo cppflags="-O3"')
+        self.check_constrain_not_changed(
+            'libelf^foo%gcc@4.5', 'libelf^foo%gcc@4.5')
+        self.check_constrain_not_changed(
+            'libelf^foo+debug', 'libelf^foo+debug')
+        self.check_constrain_not_changed(
+            'libelf^foo~debug', 'libelf^foo~debug')
+        self.check_constrain_not_changed(
+            'libelf^foo cppflags="-O3"', 'libelf^foo cppflags="-O3"')
 
         platform = spack.architecture.platform()
         default_target = platform.target('default_target').name
-        self.check_constrain_not_changed('libelf^foo target='+default_target, 'libelf^foo target='+default_target)
+        self.check_constrain_not_changed(
+            'libelf^foo target=' + default_target,
+            'libelf^foo target=' + default_target)
diff --git a/lib/spack/spack/test/spec_syntax.py b/lib/spack/spack/test/spec_syntax.py
index 4a534d7b5c..3079288c77 100644
--- a/lib/spack/spack/test/spec_syntax.py
+++ b/lib/spack/spack/test/spec_syntax.py
@@ -55,17 +55,22 @@ complex_lex = [Token(ID, 'mvapich_foo'),
 
 
 class SpecSyntaxTest(unittest.TestCase):
-    # ================================================================================
+    # ========================================================================
     # Parse checks
-    # ================================================================================
+    # ========================================================================
+
     def check_parse(self, expected, spec=None, remove_arch=True):
         """Assert that the provided spec is able to be parsed.
-           If this is called with one argument, it assumes that the string is
-           canonical (i.e., no spaces and ~ instead of - for variants) and that it
-           will convert back to the string it came from.
 
-           If this is called with two arguments, the first argument is the expected
-           canonical form and the second is a non-canonical input to be parsed.
+           If this is called with one argument, it assumes that the
+           string is canonical (i.e., no spaces and ~ instead of - for
+           variants) and that it will convert back to the string it came
+           from.
+
+           If this is called with two arguments, the first argument is
+           the expected canonical form and the second is a non-canonical
+           input to be parsed.
+
         """
         if spec is None:
             spec = expected
@@ -74,9 +79,8 @@ class SpecSyntaxTest(unittest.TestCase):
         parsed = (" ".join(str(spec) for spec in output))
         self.assertEqual(expected, parsed)
 
-
     def check_lex(self, tokens, spec):
-        """Check that the provided spec parses to the provided list of tokens."""
+        """Check that the provided spec parses to the provided token list."""
         lex_output = SpecLexer().lex(spec)
         for tok, spec_tok in zip(tokens, lex_output):
             if tok.type == ID:
@@ -85,9 +89,9 @@ class SpecSyntaxTest(unittest.TestCase):
                 # Only check the type for non-identifiers.
                 self.assertEqual(tok.type, spec_tok.type)
 
-    # ================================================================================
+    # ========================================================================
     # Parse checks
-    # ===============================================================================
+    # ========================================================================
     def test_package_names(self):
         self.check_parse("mvapich")
         self.check_parse("mvapich_foo")
@@ -104,18 +108,37 @@ class SpecSyntaxTest(unittest.TestCase):
         self.check_parse("openmpi^hwloc@1.2e6:1.4b7-rc3")
 
     def test_full_specs(self):
-        self.check_parse("mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1+debug~qt_4^stackwalker@8.1_1e")
-        self.check_parse("mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1 debug=2~qt_4^stackwalker@8.1_1e")
-        self.check_parse('mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1 cppflags="-O3"+debug~qt_4^stackwalker@8.1_1e')
+        self.check_parse(
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1+debug~qt_4"
+            "^stackwalker@8.1_1e")
+        self.check_parse(
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1 debug=2~qt_4"
+            "^stackwalker@8.1_1e")
+        self.check_parse(
+            'mvapich_foo'
+            '^_openmpi@1.2:1.4,1.6%intel@12.1 cppflags="-O3"+debug~qt_4'
+            '^stackwalker@8.1_1e')
 
     def test_canonicalize(self):
         self.check_parse(
-            "mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4^stackwalker@8.1_1e",
-            "mvapich_foo ^_openmpi@1.6,1.2:1.4%intel@12.1:12.6+debug~qt_4 ^stackwalker@8.1_1e")
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4"
+            "^stackwalker@8.1_1e",
+
+            "mvapich_foo "
+            "^_openmpi@1.6,1.2:1.4%intel@12.1:12.6+debug~qt_4 "
+            "^stackwalker@8.1_1e")
 
         self.check_parse(
-            "mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4^stackwalker@8.1_1e",
-            "mvapich_foo ^stackwalker@8.1_1e ^_openmpi@1.6,1.2:1.4%intel@12.1:12.6~qt_4+debug")
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4"
+            "^stackwalker@8.1_1e",
+
+            "mvapich_foo "
+            "^stackwalker@8.1_1e "
+            "^_openmpi@1.6,1.2:1.4%intel@12.1:12.6~qt_4+debug")
 
         self.check_parse(
             "x^y@1,2:3,4%intel@1,2,3,4+a~b+c~d+e~f",
@@ -130,58 +153,81 @@ class SpecSyntaxTest(unittest.TestCase):
         self.assertRaises(SpecParseError, self.check_parse, "x::")
 
     def test_duplicate_variant(self):
-        self.assertRaises(DuplicateVariantError, self.check_parse, "x@1.2+debug+debug")
-        self.assertRaises(DuplicateVariantError, self.check_parse, "x ^y@1.2+debug debug=true")
-        self.assertRaises(DuplicateVariantError, self.check_parse, "x ^y@1.2 debug=false debug=true")
-        self.assertRaises(DuplicateVariantError, self.check_parse, "x ^y@1.2 debug=false~debug")
-
+        self.assertRaises(DuplicateVariantError,
+                          self.check_parse, "x@1.2+debug+debug")
+        self.assertRaises(DuplicateVariantError,
+                          self.check_parse, "x ^y@1.2+debug debug=true")
+        self.assertRaises(DuplicateVariantError, self.check_parse,
+                          "x ^y@1.2 debug=false debug=true")
+        self.assertRaises(DuplicateVariantError,
+                          self.check_parse, "x ^y@1.2 debug=false~debug")
 
     def test_duplicate_depdendence(self):
-        self.assertRaises(DuplicateDependencyError, self.check_parse, "x ^y ^y")
+        self.assertRaises(DuplicateDependencyError,
+                          self.check_parse, "x ^y ^y")
 
     def test_duplicate_compiler(self):
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x%intel%intel")
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x%intel%gcc")
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x%gcc%intel")
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x ^y%intel%intel")
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x ^y%intel%gcc")
-        self.assertRaises(DuplicateCompilerSpecError, self.check_parse, "x ^y%gcc%intel")
-
-
-    # ================================================================================
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x%intel%intel")
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x%intel%gcc")
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x%gcc%intel")
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x ^y%intel%intel")
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x ^y%intel%gcc")
+        self.assertRaises(DuplicateCompilerSpecError,
+                          self.check_parse, "x ^y%gcc%intel")
+
+    # ========================================================================
     # Lex checks
-    # ================================================================================
+    # ========================================================================
     def test_ambiguous(self):
         # This first one is ambiguous because - can be in an identifier AND
         # indicate disabling an option.
         self.assertRaises(
             AssertionError, self.check_lex, complex_lex,
-            "mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug-qt_4^stackwalker@8.1_1e")
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug-qt_4"
+            "^stackwalker@8.1_1e")
 
-    # The following lexes are non-ambiguous (add a space before -qt_4) and should all
-    # result in the tokens in complex_lex
+    # The following lexes are non-ambiguous (add a space before -qt_4)
+    # and should all result in the tokens in complex_lex
     def test_minimal_spaces(self):
         self.check_lex(
             complex_lex,
-            "mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug -qt_4^stackwalker@8.1_1e")
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug -qt_4"
+            "^stackwalker@8.1_1e")
         self.check_lex(
             complex_lex,
-            "mvapich_foo^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4^stackwalker@8.1_1e")
+            "mvapich_foo"
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4"
+            "^stackwalker@8.1_1e")
 
     def test_spaces_between_dependences(self):
         self.check_lex(
             complex_lex,
-            "mvapich_foo ^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug -qt_4 ^stackwalker @ 8.1_1e")
+            "mvapich_foo "
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug -qt_4 "
+            "^stackwalker @ 8.1_1e")
         self.check_lex(
             complex_lex,
-            "mvapich_foo ^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4 ^stackwalker @ 8.1_1e")
+            "mvapich_foo "
+            "^_openmpi@1.2:1.4,1.6%intel@12.1:12.6+debug~qt_4 "
+            "^stackwalker @ 8.1_1e")
 
     def test_spaces_between_options(self):
         self.check_lex(
             complex_lex,
-            "mvapich_foo ^_openmpi @1.2:1.4,1.6 %intel @12.1:12.6 +debug -qt_4 ^stackwalker @8.1_1e")
+            "mvapich_foo "
+            "^_openmpi @1.2:1.4,1.6 %intel @12.1:12.6 +debug -qt_4 "
+            "^stackwalker @8.1_1e")
 
     def test_way_too_many_spaces(self):
         self.check_lex(
             complex_lex,
-            "mvapich_foo ^ _openmpi @ 1.2 : 1.4 , 1.6 % intel @ 12.1 : 12.6 + debug - qt_4 ^ stackwalker @ 8.1_1e")
+            "mvapich_foo "
+            "^ _openmpi @1.2 : 1.4 , 1.6 % intel @ 12.1 : 12.6 + debug - qt_4 "
+            "^ stackwalker @ 8.1_1e")
diff --git a/lib/spack/spack/test/stage.py b/lib/spack/spack/test/stage.py
index d3e3bf1383..ec661bfe50 100644
--- a/lib/spack/spack/test/stage.py
+++ b/lib/spack/spack/test/stage.py
@@ -62,6 +62,7 @@ def use_tmp(use_tmp):
 
 
 class StageTest(unittest.TestCase):
+
     def setUp(self):
         """This sets up a mock archive to fetch, and a mock temp space for use
            by the Stage class.  It doesn't actually create the Stage -- that
@@ -89,7 +90,6 @@ class StageTest(unittest.TestCase):
         # be removed.
         self.working_dir = os.getcwd()
 
-
     def tearDown(self):
         """Blows away the test environment directory."""
         shutil.rmtree(test_files_dir)
@@ -100,7 +100,6 @@ class StageTest(unittest.TestCase):
         # restore spack's original tmp environment
         spack.tmp_dirs = self.old_tmp_dirs
 
-
     def get_stage_path(self, stage, stage_name):
         """Figure out where a stage should be living.  This depends on
            whether it's named.
@@ -114,7 +113,6 @@ class StageTest(unittest.TestCase):
             self.assertTrue(stage.path.startswith(spack.stage_path))
             return stage.path
 
-
     def check_setup(self, stage, stage_name):
         """Figure out whether a stage was set up correctly."""
         stage_path = self.get_stage_path(stage, stage_name)
@@ -139,14 +137,12 @@ class StageTest(unittest.TestCase):
             # Make sure the stage path is NOT a link for a non-tmp stage
             self.assertFalse(os.path.islink(stage_path))
 
-
     def check_fetch(self, stage, stage_name):
         stage_path = self.get_stage_path(stage, stage_name)
         self.assertTrue(archive_name in os.listdir(stage_path))
         self.assertEqual(join_path(stage_path, archive_name),
                          stage.fetcher.archive_file)
 
-
     def check_expand_archive(self, stage, stage_name):
         stage_path = self.get_stage_path(stage, stage_name)
         self.assertTrue(archive_name in os.listdir(stage_path))
@@ -162,19 +158,16 @@ class StageTest(unittest.TestCase):
         with open(readme) as file:
             self.assertEqual(readme_text, file.read())
 
-
     def check_chdir(self, stage, stage_name):
         stage_path = self.get_stage_path(stage, stage_name)
         self.assertEqual(os.path.realpath(stage_path), os.getcwd())
 
-
     def check_chdir_to_source(self, stage, stage_name):
         stage_path = self.get_stage_path(stage, stage_name)
         self.assertEqual(
             join_path(os.path.realpath(stage_path), archive_dir),
             os.getcwd())
 
-
     def check_destroy(self, stage, stage_name):
         """Figure out whether a stage was destroyed correctly."""
         stage_path = self.get_stage_path(stage, stage_name)
@@ -187,35 +180,30 @@ class StageTest(unittest.TestCase):
             target = os.path.realpath(stage_path)
             self.assertFalse(os.path.exists(target))
 
-
     def test_setup_and_destroy_name_with_tmp(self):
         with use_tmp(True):
             with Stage(archive_url, name=stage_name) as stage:
                 self.check_setup(stage, stage_name)
             self.check_destroy(stage, stage_name)
 
-
     def test_setup_and_destroy_name_without_tmp(self):
         with use_tmp(False):
             with Stage(archive_url, name=stage_name) as stage:
                 self.check_setup(stage, stage_name)
             self.check_destroy(stage, stage_name)
 
-
     def test_setup_and_destroy_no_name_with_tmp(self):
         with use_tmp(True):
             with Stage(archive_url) as stage:
                 self.check_setup(stage, None)
             self.check_destroy(stage, None)
 
-
     def test_setup_and_destroy_no_name_without_tmp(self):
         with use_tmp(False):
             with Stage(archive_url) as stage:
                 self.check_setup(stage, None)
             self.check_destroy(stage, None)
 
-
     def test_chdir(self):
         with Stage(archive_url, name=stage_name) as stage:
             stage.chdir()
@@ -223,7 +211,6 @@ class StageTest(unittest.TestCase):
             self.check_chdir(stage, stage_name)
         self.check_destroy(stage, stage_name)
 
-
     def test_fetch(self):
         with Stage(archive_url, name=stage_name) as stage:
             stage.fetch()
@@ -232,7 +219,6 @@ class StageTest(unittest.TestCase):
             self.check_fetch(stage, stage_name)
         self.check_destroy(stage, stage_name)
 
-
     def test_expand_archive(self):
         with Stage(archive_url, name=stage_name) as stage:
             stage.fetch()
@@ -242,8 +228,7 @@ class StageTest(unittest.TestCase):
             self.check_expand_archive(stage, stage_name)
         self.check_destroy(stage, stage_name)
 
-
-    def test_expand_archive(self):
+    def test_expand_archive_with_chdir(self):
         with Stage(archive_url, name=stage_name) as stage:
             stage.fetch()
             self.check_setup(stage, stage_name)
@@ -254,7 +239,6 @@ class StageTest(unittest.TestCase):
             self.check_chdir_to_source(stage, stage_name)
         self.check_destroy(stage, stage_name)
 
-
     def test_restage(self):
         with Stage(archive_url, name=stage_name) as stage:
             stage.fetch()
@@ -278,20 +262,17 @@ class StageTest(unittest.TestCase):
             self.assertFalse('foobar' in os.listdir(stage.source_path))
         self.check_destroy(stage, stage_name)
 
-
     def test_no_keep_without_exceptions(self):
         with Stage(archive_url, name=stage_name, keep=False) as stage:
             pass
         self.check_destroy(stage, stage_name)
 
-
     def test_keep_without_exceptions(self):
         with Stage(archive_url, name=stage_name, keep=True) as stage:
             pass
         path = self.get_stage_path(stage, stage_name)
         self.assertTrue(os.path.isdir(path))
 
-
     def test_no_keep_with_exceptions(self):
         try:
             with Stage(archive_url, name=stage_name, keep=False) as stage:
@@ -300,8 +281,7 @@ class StageTest(unittest.TestCase):
             path = self.get_stage_path(stage, stage_name)
             self.assertTrue(os.path.isdir(path))
         except:
-            pass # ignore here.
-
+            pass  # ignore here.
 
     def test_keep_exceptions(self):
         try:
@@ -311,4 +291,4 @@ class StageTest(unittest.TestCase):
             path = self.get_stage_path(stage, stage_name)
             self.assertTrue(os.path.isdir(path))
         except:
-            pass # ignore here.
+            pass  # ignore here.
diff --git a/lib/spack/spack/test/svn_fetch.py b/lib/spack/spack/test/svn_fetch.py
index 0a745a090b..9ef7593ed1 100644
--- a/lib/spack/spack/test/svn_fetch.py
+++ b/lib/spack/spack/test/svn_fetch.py
@@ -94,17 +94,15 @@ class SvnFetchTest(MockPackagesTest):
 
             self.assert_rev(rev)
 
-
     def test_fetch_default(self):
         """Test a default checkout and make sure it's on rev 1"""
         self.try_fetch(self.repo.r1, self.repo.r1_file, {
-            'svn' : self.repo.url
+            'svn': self.repo.url
         })
 
-
     def test_fetch_r1(self):
         """Test fetching an older revision (0)."""
         self.try_fetch(self.repo.r0, self.repo.r0_file, {
-            'svn'      : self.repo.url,
-            'revision' : self.repo.r0
+            'svn': self.repo.url,
+            'revision': self.repo.r0
         })
diff --git a/lib/spack/spack/test/tally_plugin.py b/lib/spack/spack/test/tally_plugin.py
index 96af1c9b21..808694d186 100644
--- a/lib/spack/spack/test/tally_plugin.py
+++ b/lib/spack/spack/test/tally_plugin.py
@@ -26,6 +26,7 @@ import os
 
 from nose.plugins import Plugin
 
+
 class Tally(Plugin):
     name = 'tally'
 
diff --git a/lib/spack/spack/test/url_extrapolate.py b/lib/spack/spack/test/url_extrapolate.py
index ffd4230f71..ca14dab958 100644
--- a/lib/spack/spack/test/url_extrapolate.py
+++ b/lib/spack/spack/test/url_extrapolate.py
@@ -34,20 +34,21 @@ class UrlExtrapolateTest(unittest.TestCase):
     def check_url(self, base, version, new_url):
         self.assertEqual(url.substitute_version(base, version), new_url)
 
-
     def test_libelf_version(self):
         base = "http://www.mr511.de/software/libelf-0.8.13.tar.gz"
         self.check_url(base, '0.8.13', base)
-        self.check_url(base, '0.8.12', "http://www.mr511.de/software/libelf-0.8.12.tar.gz")
-        self.check_url(base, '0.3.1',  "http://www.mr511.de/software/libelf-0.3.1.tar.gz")
-        self.check_url(base, '1.3.1b', "http://www.mr511.de/software/libelf-1.3.1b.tar.gz")
-
+        self.check_url(
+            base, '0.8.12', "http://www.mr511.de/software/libelf-0.8.12.tar.gz")
+        self.check_url(
+            base, '0.3.1',  "http://www.mr511.de/software/libelf-0.3.1.tar.gz")
+        self.check_url(
+            base, '1.3.1b', "http://www.mr511.de/software/libelf-1.3.1b.tar.gz")
 
     def test_libdwarf_version(self):
         base = "http://www.prevanders.net/libdwarf-20130729.tar.gz"
         self.check_url(base, '20130729', base)
-        self.check_url(base, '8.12', "http://www.prevanders.net/libdwarf-8.12.tar.gz")
-
+        self.check_url(
+            base, '8.12', "http://www.prevanders.net/libdwarf-8.12.tar.gz")
 
     def test_dyninst_version(self):
         # Dyninst has a version twice in the URL.
@@ -58,7 +59,6 @@ class UrlExtrapolateTest(unittest.TestCase):
         self.check_url(base, '8.3.1',
                        "http://www.dyninst.org/sites/default/files/downloads/dyninst/8.3.1/DyninstAPI-8.3.1.tgz")
 
-
     def test_partial_version_prefix(self):
         # Test now with a partial prefix earlier in the URL -- this is
         # hard to figure out so Spack only substitutes the last
@@ -72,7 +72,6 @@ class UrlExtrapolateTest(unittest.TestCase):
         self.check_url(base, '8.3.1',
                        "http://www.dyninst.org/sites/default/files/downloads/dyninst/8.1/DyninstAPI-8.3.1.tgz")
 
-
     def test_scalasca_partial_version(self):
         # Note that this probably doesn't actually work, but sites are
         # inconsistent about their directory structure, so it's not
@@ -84,19 +83,16 @@ class UrlExtrapolateTest(unittest.TestCase):
         self.check_url('http://apps.fz-juelich.de/scalasca/releases/cube/4.3/dist/cube-4.3-TP1.tar.gz', '8.3.1',
                        'http://apps.fz-juelich.de/scalasca/releases/cube/4.3/dist/cube-8.3.1.tar.gz')
 
-
     def test_mpileaks_version(self):
         self.check_url('https://github.com/hpc/mpileaks/releases/download/v1.0/mpileaks-1.0.tar.gz', '2.1.3',
                        'https://github.com/hpc/mpileaks/releases/download/v2.1.3/mpileaks-2.1.3.tar.gz')
 
-
     def test_gcc(self):
         self.check_url('http://open-source-box.org/gcc/gcc-4.9.2/gcc-4.9.2.tar.bz2', '4.7',
                        'http://open-source-box.org/gcc/gcc-4.7/gcc-4.7.tar.bz2')
         self.check_url('http://open-source-box.org/gcc/gcc-4.4.7/gcc-4.4.7.tar.bz2', '4.4.7',
                        'http://open-source-box.org/gcc/gcc-4.4.7/gcc-4.4.7.tar.bz2')
 
-
     def test_github_raw(self):
         self.check_url('https://github.com/losalamos/CLAMR/blob/packages/PowerParser_v2.0.7.tgz?raw=true', '2.0.7',
                        'https://github.com/losalamos/CLAMR/blob/packages/PowerParser_v2.0.7.tgz?raw=true')
diff --git a/lib/spack/spack/test/url_parse.py b/lib/spack/spack/test/url_parse.py
index 648996aaaa..6c944a3e7a 100644
--- a/lib/spack/spack/test/url_parse.py
+++ b/lib/spack/spack/test/url_parse.py
@@ -32,11 +32,11 @@ import spack.url as url
 
 
 class UrlParseTest(unittest.TestCase):
+
     def assert_not_detected(self, string):
         self.assertRaises(
             url.UndetectableVersionError, url.parse_name_and_version, string)
 
-
     def check(self, name, v, string, **kwargs):
         # Make sure correct name and version are extracted.
         parsed_name, parsed_v = url.parse_name_and_version(string)
@@ -52,7 +52,6 @@ class UrlParseTest(unittest.TestCase):
         # build one with a specific version.
         self.assertEqual(string, url.substitute_version(string, v))
 
-
     def test_wwwoffle_version(self):
         self.check(
             'wwwoffle', '2.9h',
@@ -72,7 +71,7 @@ class UrlParseTest(unittest.TestCase):
 
     def test_version_all_dots(self):
         self.check(
-            'foo.bar.la', '1.14','http://example.com/foo.bar.la.1.14.zip')
+            'foo.bar.la', '1.14', 'http://example.com/foo.bar.la.1.14.zip')
 
     def test_version_underscore_separator(self):
         self.check(
@@ -286,7 +285,7 @@ class UrlParseTest(unittest.TestCase):
             'mvapich2', '1.9',
             'http://mvapich.cse.ohio-state.edu/download/mvapich2/mv2/mvapich2-1.9.tgz')
 
-    def test_mvapich2_19_version(self):
+    def test_mvapich2_20_version(self):
         self.check(
             'mvapich2', '2.0',
             'http://mvapich.cse.ohio-state.edu/download/mvapich/mv2/mvapich2-2.0.tar.gz')
diff --git a/lib/spack/spack/test/url_substitution.py b/lib/spack/spack/test/url_substitution.py
index 9cc04834b6..ea6374e3d2 100644
--- a/lib/spack/spack/test/url_substitution.py
+++ b/lib/spack/spack/test/url_substitution.py
@@ -26,37 +26,31 @@
 This test does sanity checks on substituting new versions into URLs
 """
 import unittest
-
 import spack.url as url
 
 
+base = "https://comp.llnl.gov/linear_solvers/download/hypre-2.9.0b.tar.gz"
+stem = "https://comp.llnl.gov/linear_solvers/download/hypre-"
+
+
 class PackageSanityTest(unittest.TestCase):
-    def test_hypre_url_substitution(self):
-        base = "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-2.9.0b.tar.gz"
 
+    def test_hypre_url_substitution(self):
         self.assertEqual(url.substitute_version(base, '2.9.0b'), base)
         self.assertEqual(
-            url.substitute_version(base, '2.8.0b'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-2.8.0b.tar.gz")
+            url.substitute_version(base, '2.8.0b'), stem + "2.8.0b.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '2.7.0b'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-2.7.0b.tar.gz")
+            url.substitute_version(base, '2.7.0b'), stem + "2.7.0b.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '2.6.0b'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-2.6.0b.tar.gz")
+            url.substitute_version(base, '2.6.0b'), stem + "2.6.0b.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '1.14.0b'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-1.14.0b.tar.gz")
+            url.substitute_version(base, '1.14.0b'), stem + "1.14.0b.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '1.13.0b'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-1.13.0b.tar.gz")
+            url.substitute_version(base, '1.13.0b'), stem + "1.13.0b.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '2.0.0'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-2.0.0.tar.gz")
+            url.substitute_version(base, '2.0.0'), stem + "2.0.0.tar.gz")
         self.assertEqual(
-            url.substitute_version(base, '1.6.0'),
-            "https://computation-rnd.llnl.gov/linear_solvers/download/hypre-1.6.0.tar.gz")
-
+            url.substitute_version(base, '1.6.0'), stem + "1.6.0.tar.gz")
 
     def test_otf2_url_substitution(self):
         base = "http://www.vi-hps.org/upload/packages/otf2/otf2-1.4.tar.gz"
diff --git a/lib/spack/spack/test/yaml.py b/lib/spack/spack/test/yaml.py
index f1b83e7b71..dedbd15d10 100644
--- a/lib/spack/spack/test/yaml.py
+++ b/lib/spack/spack/test/yaml.py
@@ -45,26 +45,25 @@ config_file:
 """
 
 test_data = {
-    'config_file' : syaml.syaml_dict([
+    'config_file': syaml.syaml_dict([
         ('x86_64', syaml.syaml_dict([
             ('foo', '/path/to/foo'),
             ('bar', '/path/to/bar'),
-            ('baz', '/path/to/baz' )])),
-        ('some_list', [ 'item 1', 'item 2', 'item 3' ]),
-        ('another_list', [ 1, 2, 3 ]),
+            ('baz', '/path/to/baz')])),
+        ('some_list', ['item 1', 'item 2', 'item 3']),
+        ('another_list', [1, 2, 3]),
         ('some_key', 'some_string')
     ])}
 
+
 class YamlTest(unittest.TestCase):
 
     def setUp(self):
         self.data = syaml.load(test_file)
 
-
     def test_parse(self):
         self.assertEqual(test_data, self.data)
 
-
     def test_dict_order(self):
         self.assertEqual(
             ['x86_64', 'some_list', 'another_list', 'some_key'],
@@ -74,7 +73,6 @@ class YamlTest(unittest.TestCase):
             ['foo', 'bar', 'baz'],
             self.data['config_file']['x86_64'].keys())
 
-
     def test_line_numbers(self):
         def check(obj, start_line, end_line):
             self.assertEqual(obj._start_mark.line, start_line)
diff --git a/lib/spack/spack/url.py b/lib/spack/spack/url.py
index f678a2dca9..02c9c04380 100644
--- a/lib/spack/spack/url.py
+++ b/lib/spack/spack/url.py
@@ -56,12 +56,12 @@ import spack.error
 import spack.util.compression as comp
 from spack.version import Version
 
+
 #
 # Note: We call the input to most of these functions a "path" but the functions
 # work on paths and URLs.  There's not a good word for both of these, but
 # "path" seemed like the most generic term.
 #
-
 def find_list_url(url):
     """Finds a good list URL for the supplied URL.  This depends on
        the site.  By default, just assumes that a good list URL is the
@@ -71,8 +71,8 @@ def find_list_url(url):
 
     url_types = [
         # e.g. https://github.com/llnl/callpath/archive/v1.0.1.tar.gz
-        (r'^(https://github.com/[^/]+/[^/]+)/archive/', lambda m: m.group(1) + '/releases')
-        ]
+        (r'^(https://github.com/[^/]+/[^/]+)/archive/',
+         lambda m: m.group(1) + '/releases')]
 
     for pattern, fun in url_types:
         match = re.search(pattern, url)
@@ -89,8 +89,10 @@ def strip_query_and_fragment(path):
 
         query, frag = components[3:5]
         suffix = ''
-        if query: suffix += '?' + query
-        if frag:  suffix += '#' + frag
+        if query:
+            suffix += '?' + query
+        if frag:
+            suffix += '#' + frag
 
         return (urlunsplit(stripped), suffix)
 
@@ -152,8 +154,10 @@ def downloaded_file_extension(path):
     """
     match = re.search(r'github.com/.+/(zip|tar)ball/', path)
     if match:
-        if   match.group(1) == 'zip': return 'zip'
-        elif match.group(1) == 'tar': return 'tar.gz'
+        if match.group(1) == 'zip':
+            return 'zip'
+        elif match.group(1) == 'tar':
+            return 'tar.gz'
 
     prefix, ext, suffix = split_url_extension(path)
     if not ext:
@@ -193,7 +197,8 @@ def parse_version_offset(path):
         (r'[-_](R\d+[AB]\d*(-\d+)?)', path),
 
         # e.g., https://github.com/hpc/libcircle/releases/download/0.2.1-rc.1/libcircle-0.2.1-rc.1.tar.gz
-        # e.g., https://github.com/hpc/mpileaks/releases/download/v1.0/mpileaks-1.0.tar.gz
+        # e.g.,
+        # https://github.com/hpc/mpileaks/releases/download/v1.0/mpileaks-1.0.tar.gz
         (r'github.com/[^/]+/[^/]+/releases/download/v?([^/]+)/.*$', path),
 
         # e.g. boost_1_39_0
@@ -201,7 +206,7 @@ def parse_version_offset(path):
 
         # e.g. foobar-4.5.1-1
         # e.g. ruby-1.9.1-p243
-        (r'-((\d+\.)*\d\.\d+-(p|rc|RC)?\d+)(?:[-._](?:bin|dist|stable|src|sources))?$', stem),
+        (r'-((\d+\.)*\d\.\d+-(p|rc|RC)?\d+)(?:[-._](?:bin|dist|stable|src|sources))?$', stem),  # noqa
 
         # e.g. lame-398-1
         (r'-((\d)+-\d)', stem),
@@ -275,7 +280,8 @@ def parse_name_offset(path, v=None):
 
     name_types = [
         (r'/sourceforge/([^/]+)/', path),
-        (r'github.com/[^/]+/[^/]+/releases/download/%s/(.*)-%s$' % (v, v), path),
+        (r'github.com/[^/]+/[^/]+/releases/download/%s/(.*)-%s$' %
+         (v, v), path),
         (r'/([^/]+)/(tarball|zipball)/', path),
         (r'/([^/]+)[_.-](bin|dist|stable|src|sources)[_.-]%s' % v, path),
         (r'github.com/[^/]+/([^/]+)/archive', path),
@@ -283,7 +289,8 @@ def parse_name_offset(path, v=None):
         (r'([^/]+)[_.-]v?%s' % v, stem),   # prefer the stem
         (r'([^/]+)%s' % v, stem),
 
-        (r'/([^/]+)[_.-]v?%s' % v, path),   # accept the path if name is not in stem.
+        # accept the path if name is not in stem.
+        (r'/([^/]+)[_.-]v?%s' % v, path),
         (r'/([^/]+)%s' % v, path),
 
         (r'^([^/]+)[_.-]v?%s' % v, path),
@@ -326,7 +333,7 @@ def insensitize(string):
     return re.sub(r'([a-zA-Z])', to_ins, string)
 
 
-def cumsum(elts, init=0, fn=lambda x:x):
+def cumsum(elts, init=0, fn=lambda x: x):
     """Return cumulative sum of result of fn on each element in elts."""
     sums = []
     s = init
@@ -337,21 +344,20 @@ def cumsum(elts, init=0, fn=lambda x:x):
 
 
 def substitution_offsets(path):
-    """This returns offsets for substituting versions and names in the provided path.
-       It is a helper for substitute_version().
+    """This returns offsets for substituting versions and names in the
+       provided path.  It is a helper for substitute_version().
     """
     # Get name and version offsets
     try:
         ver,  vs, vl = parse_version_offset(path)
         name, ns, nl = parse_name_offset(path, ver)
-    except UndetectableNameError, e:
+    except UndetectableNameError:
         return (None, -1, -1, (), ver, vs, vl, (vs,))
-    except UndetectableVersionError, e:
+    except UndetectableVersionError:
         return (None, -1, -1, (), None, -1, -1, ())
 
     # protect extensions like bz2 from getting inadvertently
     # considered versions.
-    ext = comp.extension(path)
     path = comp.strip_extension(path)
 
     # Construct a case-insensitive regular expression for the package name.
@@ -449,7 +455,7 @@ def color_url(path, **kwargs):
           Cyan: The version found by parse_version_offset().
           Red:  The name found by parse_name_offset().
 
-          Green:   Instances of version string substituted by substitute_version().
+          Green:   Instances of version string from substitute_version().
           Magenta: Instances of the name (protected from substitution).
 
        Optional args:
@@ -469,31 +475,46 @@ def color_url(path, **kwargs):
     nerr = verr = 0
     out = StringIO()
     for i in range(len(path)):
-        if   i == vs:    out.write('@c'); verr += 1
-        elif i == ns:    out.write('@r'); nerr += 1
+        if i == vs:
+            out.write('@c')
+            verr += 1
+        elif i == ns:
+            out.write('@r')
+            nerr += 1
         elif subs:
-            if i in voffs: out.write('@g')
-            elif i in noffs: out.write('@m')
+            if i in voffs:
+                out.write('@g')
+            elif i in noffs:
+                out.write('@m')
 
         out.write(path[i])
 
-        if   i == vs + vl - 1:  out.write('@.'); verr += 1
-        elif i == ns + nl - 1:  out.write('@.'); nerr += 1
+        if i == vs + vl - 1:
+            out.write('@.')
+            verr += 1
+        elif i == ns + nl - 1:
+            out.write('@.')
+            nerr += 1
         elif subs:
             if i in vends or i in nends:
                 out.write('@.')
 
     if errors:
-        if nerr == 0: out.write(" @r{[no name]}")
-        if verr == 0: out.write(" @r{[no version]}")
-        if nerr == 1: out.write(" @r{[incomplete name]}")
-        if verr == 1: out.write(" @r{[incomplete version]}")
+        if nerr == 0:
+            out.write(" @r{[no name]}")
+        if verr == 0:
+            out.write(" @r{[no version]}")
+        if nerr == 1:
+            out.write(" @r{[incomplete name]}")
+        if verr == 1:
+            out.write(" @r{[incomplete version]}")
 
     return colorize(out.getvalue())
 
 
 class UrlParseError(spack.error.SpackError):
     """Raised when the URL module can't parse something correctly."""
+
     def __init__(self, msg, path):
         super(UrlParseError, self).__init__(msg)
         self.path = path
@@ -501,6 +522,7 @@ class UrlParseError(spack.error.SpackError):
 
 class UndetectableVersionError(UrlParseError):
     """Raised when we can't parse a version from a string."""
+
     def __init__(self, path):
         super(UndetectableVersionError, self).__init__(
             "Couldn't detect version in: " + path, path)
@@ -508,6 +530,7 @@ class UndetectableVersionError(UrlParseError):
 
 class UndetectableNameError(UrlParseError):
     """Raised when we can't parse a package name from a string."""
+
     def __init__(self, path):
         super(UndetectableNameError, self).__init__(
             "Couldn't parse package name in: " + path, path)
diff --git a/lib/spack/spack/util/compression.py b/lib/spack/spack/util/compression.py
index dc1188eb0f..64554ab2f7 100644
--- a/lib/spack/spack/util/compression.py
+++ b/lib/spack/spack/util/compression.py
@@ -32,7 +32,9 @@ PRE_EXTS = ["tar"]
 EXTS     = ["gz", "bz2", "xz", "Z", "zip", "tgz"]
 
 # Add PRE_EXTS and EXTS last so that .tar.gz is matched *before* .tar or .gz
-ALLOWED_ARCHIVE_TYPES = [".".join(l) for l in product(PRE_EXTS, EXTS)] + PRE_EXTS + EXTS
+ALLOWED_ARCHIVE_TYPES = [".".join(l) for l in product(
+    PRE_EXTS, EXTS)] + PRE_EXTS + EXTS
+
 
 def allowed_archive(path):
     return any(path.endswith(t) for t in ALLOWED_ARCHIVE_TYPES)
diff --git a/lib/spack/spack/util/crypto.py b/lib/spack/spack/util/crypto.py
index 1ae9793518..22777fdb68 100644
--- a/lib/spack/spack/util/crypto.py
+++ b/lib/spack/spack/util/crypto.py
@@ -31,7 +31,7 @@ _acceptable_hashes = [
     hashlib.sha224,
     hashlib.sha256,
     hashlib.sha384,
-    hashlib.sha512 ]
+    hashlib.sha512]
 
 """Index for looking up hasher for a digest."""
 _size_to_hash = dict((h().digest_size, h) for h in _acceptable_hashes)
@@ -52,7 +52,6 @@ def checksum(hashlib_algo, filename, **kwargs):
     return hasher.hexdigest()
 
 
-
 class Checker(object):
     """A checker checks files against one particular hex digest.
        It will automatically determine what hashing algorithm
@@ -74,25 +73,25 @@ class Checker(object):
        adjusting the block_size optional arg.  By default it's
        a 1MB (2**20 bytes) buffer.
     """
+
     def __init__(self, hexdigest, **kwargs):
         self.block_size = kwargs.get('block_size', 2**20)
         self.hexdigest = hexdigest
         self.sum       = None
 
         bytes = len(hexdigest) / 2
-        if not bytes in _size_to_hash:
+        if bytes not in _size_to_hash:
             raise ValueError(
-                'Spack knows no hash algorithm for this digest: %s' % hexdigest)
+                'Spack knows no hash algorithm for this digest: %s'
+                % hexdigest)
 
         self.hash_fun = _size_to_hash[bytes]
 
-
     @property
     def hash_name(self):
         """Get the name of the hash function this Checker is using."""
         return self.hash_fun().name
 
-
     def check(self, filename):
         """Read the file with the specified name and check its checksum
            against self.hexdigest.  Return True if they match, False
diff --git a/lib/spack/spack/util/debug.py b/lib/spack/spack/util/debug.py
index e8a0595416..cf485a611d 100644
--- a/lib/spack/spack/util/debug.py
+++ b/lib/spack/spack/util/debug.py
@@ -33,10 +33,11 @@ import code
 import traceback
 import signal
 
+
 def debug_handler(sig, frame):
     """Interrupt running process, and provide a python prompt for
     interactive debugging."""
-    d = {'_frame':frame}         # Allow access to frame object.
+    d = {'_frame': frame}         # Allow access to frame object.
     d.update(frame.f_globals)    # Unless shadowed by global
     d.update(frame.f_locals)
 
@@ -48,5 +49,5 @@ def debug_handler(sig, frame):
 
 
 def register_interrupt_handler():
-    """Register a handler to print a stack trace and enter an interpreter on Ctrl-C"""
+    """Print traceback and enter an interpreter on Ctrl-C"""
     signal.signal(signal.SIGINT, debug_handler)
diff --git a/lib/spack/spack/util/executable.py b/lib/spack/spack/util/executable.py
index 14b56e8d6c..5c27b92df5 100644
--- a/lib/spack/spack/util/executable.py
+++ b/lib/spack/spack/util/executable.py
@@ -165,7 +165,6 @@ class Executable(object):
                 raise ProcessError("Command exited with status %d:" %
                                    proc.returncode, cmd_line)
 
-
             if output is str or error is str:
                 result = ''
                 if output is str:
@@ -227,6 +226,7 @@ def which(name, **kwargs):
 
 
 class ProcessError(spack.error.SpackError):
+
     def __init__(self, msg, long_message=None):
         # These are used for detailed debugging information for
         # package builds.  They're built up gradually as the exception
diff --git a/lib/spack/spack/util/multiproc.py b/lib/spack/spack/util/multiproc.py
index 038cd90121..6a25c45713 100644
--- a/lib/spack/spack/util/multiproc.py
+++ b/lib/spack/spack/util/multiproc.py
@@ -32,18 +32,21 @@ from itertools import izip
 
 __all__ = ['spawn', 'parmap', 'Barrier']
 
+
 def spawn(f):
-    def fun(pipe,x):
+    def fun(pipe, x):
         pipe.send(f(x))
         pipe.close()
     return fun
 
-def parmap(f,X):
-    pipe=[Pipe() for x in X]
-    proc=[Process(target=spawn(f),args=(c,x)) for x,(p,c) in izip(X,pipe)]
+
+def parmap(f, X):
+    pipe = [Pipe() for x in X]
+    proc = [Process(target=spawn(f), args=(c, x))
+            for x, (p, c) in izip(X, pipe)]
     [p.start() for p in proc]
     [p.join() for p in proc]
-    return [p.recv() for (p,c) in pipe]
+    return [p.recv() for (p, c) in pipe]
 
 
 class Barrier:
@@ -53,6 +56,7 @@ class Barrier:
 
     See http://greenteapress.com/semaphores/downey08semaphores.pdf, p. 41.
     """
+
     def __init__(self, n, timeout=None):
         self.n = n
         self.to = timeout
@@ -61,7 +65,6 @@ class Barrier:
         self.turnstile1 = Semaphore(0)
         self.turnstile2 = Semaphore(1)
 
-
     def wait(self):
         if not self.mutex.acquire(timeout=self.to):
             raise BarrierTimeoutError()
@@ -90,4 +93,5 @@ class Barrier:
         self.turnstile2.release()
 
 
-class BarrierTimeoutError: pass
+class BarrierTimeoutError:
+    pass
diff --git a/lib/spack/spack/util/naming.py b/lib/spack/spack/util/naming.py
index 2d9762942d..9a5cdee411 100644
--- a/lib/spack/spack/util/naming.py
+++ b/lib/spack/spack/util/naming.py
@@ -31,9 +31,15 @@ from StringIO import StringIO
 
 import spack
 
-__all__ = ['mod_to_class', 'spack_module_to_python_module', 'valid_module_name',
-           'valid_fully_qualified_module_name', 'validate_fully_qualified_module_name',
-           'validate_module_name', 'possible_spack_module_names', 'NamespaceTrie']
+__all__ = [
+    'mod_to_class',
+    'spack_module_to_python_module',
+    'valid_module_name',
+    'valid_fully_qualified_module_name',
+    'validate_fully_qualified_module_name',
+    'validate_module_name',
+    'possible_spack_module_names',
+    'NamespaceTrie']
 
 # Valid module names can contain '-' but can't start with it.
 _valid_module_re = r'^\w[\w-]*$'
@@ -67,8 +73,8 @@ def mod_to_class(mod_name):
     class_name = string.capwords(class_name, '-')
     class_name = class_name.replace('-', '')
 
-    # If a class starts with a number, prefix it with Number_ to make it a valid
-    # Python class name.
+    # If a class starts with a number, prefix it with Number_ to make it
+    # a valid Python class name.
     if re.match(r'^[0-9]', class_name):
         class_name = "_%s" % class_name
 
@@ -126,6 +132,7 @@ def validate_fully_qualified_module_name(mod_name):
 
 class InvalidModuleNameError(spack.error.SpackError):
     """Raised when we encounter a bad module name."""
+
     def __init__(self, name):
         super(InvalidModuleNameError, self).__init__(
             "Invalid module name: " + name)
@@ -134,6 +141,7 @@ class InvalidModuleNameError(spack.error.SpackError):
 
 class InvalidFullyQualifiedModuleNameError(spack.error.SpackError):
     """Raised when we encounter a bad full package name."""
+
     def __init__(self, name):
         super(InvalidFullyQualifiedModuleNameError, self).__init__(
             "Invalid fully qualified package name: " + name)
@@ -141,17 +149,17 @@ class InvalidFullyQualifiedModuleNameError(spack.error.SpackError):
 
 
 class NamespaceTrie(object):
+
     class Element(object):
+
         def __init__(self, value):
             self.value = value
 
-
     def __init__(self, separator='.'):
         self._subspaces = {}
         self._value = None
         self._sep = separator
 
-
     def __setitem__(self, namespace, value):
         first, sep, rest = namespace.partition(self._sep)
 
@@ -164,7 +172,6 @@ class NamespaceTrie(object):
 
         self._subspaces[first][rest] = value
 
-
     def _get_helper(self, namespace, full_name):
         first, sep, rest = namespace.partition(self._sep)
         if not first:
@@ -176,13 +183,12 @@ class NamespaceTrie(object):
         else:
             return self._subspaces[first]._get_helper(rest, full_name)
 
-
     def __getitem__(self, namespace):
         return self._get_helper(namespace, namespace)
 
-
     def is_prefix(self, namespace):
-        """True if the namespace has a value, or if it's the prefix of one that does."""
+        """True if the namespace has a value, or if it's the prefix of one that
+           does."""
         first, sep, rest = namespace.partition(self._sep)
         if not first:
             return True
@@ -191,7 +197,6 @@ class NamespaceTrie(object):
         else:
             return self._subspaces[first].is_prefix(rest)
 
-
     def is_leaf(self, namespace):
         """True if this namespace has no children in the trie."""
         first, sep, rest = namespace.partition(self._sep)
@@ -202,7 +207,6 @@ class NamespaceTrie(object):
         else:
             return self._subspaces[first].is_leaf(rest)
 
-
     def has_value(self, namespace):
         """True if there is a value set for the given namespace."""
         first, sep, rest = namespace.partition(self._sep)
@@ -213,20 +217,17 @@ class NamespaceTrie(object):
         else:
             return self._subspaces[first].has_value(rest)
 
-
     def __contains__(self, namespace):
         """Returns whether a value has been set for the namespace."""
         return self.has_value(namespace)
 
-
     def _str_helper(self, stream, level=0):
         indent = (level * '    ')
         for name in sorted(self._subspaces):
             stream.write(indent + name + '\n')
             if self._value:
                 stream.write(indent + '  ' + repr(self._value.value))
-            stream.write(self._subspaces[name]._str_helper(stream, level+1))
-
+            stream.write(self._subspaces[name]._str_helper(stream, level + 1))
 
     def __str__(self):
         stream = StringIO()
diff --git a/lib/spack/spack/util/pattern.py b/lib/spack/spack/util/pattern.py
index bc5e9d2ffe..c36445193c 100644
--- a/lib/spack/spack/util/pattern.py
+++ b/lib/spack/spack/util/pattern.py
@@ -53,7 +53,9 @@ def composite(interface=None, method_list=None, container=list):
     # Check if at least one of the 'interface' or the 'method_list' arguments
     # are defined
     if interface is None and method_list is None:
-        raise TypeError("Either 'interface' or 'method_list' must be defined on a call to composite")  # NOQA : ignore=E501
+        raise TypeError(
+            "Either 'interface' or 'method_list' must be defined on a call "
+            "to composite")
 
     def cls_decorator(cls):
         # Retrieve the base class of the composite. Inspect its methods and
@@ -102,7 +104,8 @@ def composite(interface=None, method_list=None, container=list):
             # python@2.7: interface_methods = {name: method for name, method in
             # inspect.getmembers(interface, predicate=no_special_no_private)}
             interface_methods = {}
-            for name, method in inspect.getmembers(interface, predicate=no_special_no_private):  # NOQA: ignore=E501
+            for name, method in inspect.getmembers(
+                    interface, predicate=no_special_no_private):
                 interface_methods[name] = method
             ##########
             # python@2.7: interface_methods_dict = {name: IterateOver(name,
@@ -118,7 +121,8 @@ def composite(interface=None, method_list=None, container=list):
         # python@2.7: cls_method = {name: method for name, method in
         # inspect.getmembers(cls, predicate=inspect.ismethod)}
         cls_method = {}
-        for name, method in inspect.getmembers(cls, predicate=inspect.ismethod):  # NOQA: ignore=E501
+        for name, method in inspect.getmembers(
+                cls, predicate=inspect.ismethod):
             cls_method[name] = method
         ##########
         dictionary_for_type_call.update(cls_method)
diff --git a/lib/spack/spack/util/prefix.py b/lib/spack/spack/util/prefix.py
index e1a0f2958b..985d862269 100644
--- a/lib/spack/spack/util/prefix.py
+++ b/lib/spack/spack/util/prefix.py
@@ -27,6 +27,7 @@ This file contains utilities to help with installing packages.
 """
 from llnl.util.filesystem import join_path
 
+
 class Prefix(str):
     """This class represents an installation prefix, but provides useful
        attributes for referring to directories inside the prefix.
diff --git a/lib/spack/spack/util/spack_yaml.py b/lib/spack/spack/util/spack_yaml.py
index 909f9a57a8..7bcdf2d61f 100644
--- a/lib/spack/spack/util/spack_yaml.py
+++ b/lib/spack/spack/util/spack_yaml.py
@@ -34,7 +34,6 @@
 import yaml
 from yaml.nodes import *
 from yaml.constructor import ConstructorError
-from yaml.representer import SafeRepresenter
 from ordereddict_backport import OrderedDict
 
 # Only export load and dump
@@ -42,15 +41,23 @@ __all__ = ['load', 'dump']
 
 # Make new classes so we can add custom attributes.
 # Also, use OrderedDict instead of just dict.
+
+
 class syaml_dict(OrderedDict):
+
     def __repr__(self):
-        mappings = ('%r: %r' % (k,v) for k,v in self.items())
+        mappings = ('%r: %r' % (k, v) for k, v in self.items())
         return '{%s}' % ', '.join(mappings)
+
+
 class syaml_list(list):
     __repr__ = list.__repr__
+
+
 class syaml_str(str):
     __repr__ = str.__repr__
 
+
 def mark(obj, node):
     """Add start and end markers to an object."""
     obj._start_mark = node.start_mark
@@ -73,6 +80,7 @@ class OrderedLineLoader(yaml.Loader):
     # The standard YAML constructors return empty instances and fill
     # in with mappings later.  We preserve this behavior.
     #
+
     def construct_yaml_str(self, node):
         value = self.construct_scalar(node)
         try:
@@ -83,14 +91,12 @@ class OrderedLineLoader(yaml.Loader):
         mark(value, node)
         return value
 
-
     def construct_yaml_seq(self, node):
         data = syaml_list()
         mark(data, node)
         yield data
         data.extend(self.construct_sequence(node))
 
-
     def construct_yaml_map(self, node):
         data = syaml_dict()
         mark(data, node)
@@ -104,22 +110,23 @@ class OrderedLineLoader(yaml.Loader):
     #
     def construct_sequence(self, node, deep=False):
         if not isinstance(node, SequenceNode):
-            raise ConstructorError(None, None,
-                    "expected a sequence node, but found %s" % node.id,
-                    node.start_mark)
-        value =  syaml_list(self.construct_object(child, deep=deep)
-                             for child in node.value)
+            raise ConstructorError(
+                None, None,
+                "expected a sequence node, but found %s" % node.id,
+                node.start_mark)
+        value = syaml_list(self.construct_object(child, deep=deep)
+                           for child in node.value)
         mark(value, node)
         return value
 
-
     def construct_mapping(self, node, deep=False):
         """Store mappings as OrderedDicts instead of as regular python
            dictionaries to preserve file ordering."""
         if not isinstance(node, MappingNode):
-            raise ConstructorError(None, None,
-                    "expected a mapping node, but found %s" % node.id,
-                    node.start_mark)
+            raise ConstructorError(
+                None, None,
+                "expected a mapping node, but found %s" % node.id,
+                node.start_mark)
 
         mapping = syaml_dict()
         for key_node, value_node in node.value:
@@ -127,22 +134,26 @@ class OrderedLineLoader(yaml.Loader):
             try:
                 hash(key)
             except TypeError, exc:
-                raise ConstructorError("while constructing a mapping", node.start_mark,
-                        "found unacceptable key (%s)" % exc, key_node.start_mark)
+                raise ConstructorError(
+                    "while constructing a mapping", node.start_mark,
+                    "found unacceptable key (%s)" % exc, key_node.start_mark)
             value = self.construct_object(value_node, deep=deep)
             if key in mapping:
-                raise ConstructorError("while constructing a mapping", node.start_mark,
-                                       "found already in-use key (%s)" % key, key_node.start_mark)
+                raise ConstructorError(
+                    "while constructing a mapping", node.start_mark,
+                    "found already in-use key (%s)" % key, key_node.start_mark)
             mapping[key] = value
 
         mark(mapping, node)
         return mapping
 
 # register above new constructors
-OrderedLineLoader.add_constructor(u'tag:yaml.org,2002:map', OrderedLineLoader.construct_yaml_map)
-OrderedLineLoader.add_constructor(u'tag:yaml.org,2002:seq', OrderedLineLoader.construct_yaml_seq)
-OrderedLineLoader.add_constructor(u'tag:yaml.org,2002:str', OrderedLineLoader.construct_yaml_str)
-
+OrderedLineLoader.add_constructor(
+    u'tag:yaml.org,2002:map', OrderedLineLoader.construct_yaml_map)
+OrderedLineLoader.add_constructor(
+    u'tag:yaml.org,2002:seq', OrderedLineLoader.construct_yaml_seq)
+OrderedLineLoader.add_constructor(
+    u'tag:yaml.org,2002:str', OrderedLineLoader.construct_yaml_str)
 
 
 class OrderedLineDumper(yaml.Dumper):
@@ -154,6 +165,7 @@ class OrderedLineDumper(yaml.Dumper):
       regular Python equivalents, instead of ugly YAML pyobjects.
 
     """
+
     def represent_mapping(self, tag, mapping, flow_style=None):
         value = []
         node = MappingNode(tag, value, flow_style=flow_style)
@@ -173,7 +185,8 @@ class OrderedLineDumper(yaml.Dumper):
             node_value = self.represent_data(item_value)
             if not (isinstance(node_key, ScalarNode) and not node_key.style):
                 best_style = False
-            if not (isinstance(node_value, ScalarNode) and not node_value.style):
+            if not (isinstance(node_value, ScalarNode) and
+                    not node_value.style):
                 best_style = False
             value.append((node_key, node_value))
         if flow_style is None:
diff --git a/lib/spack/spack/util/string.py b/lib/spack/spack/util/string.py
index ce017b8126..dae7afbf46 100644
--- a/lib/spack/spack/util/string.py
+++ b/lib/spack/spack/util/string.py
@@ -23,6 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 
+
 def comma_list(sequence, article=''):
     if type(sequence) != list:
         sequence = list(sequence)
@@ -32,7 +33,7 @@ def comma_list(sequence, article=''):
     elif len(sequence) == 1:
         return sequence[0]
     else:
-        out =  ', '.join(str(s) for s in sequence[:-1])
+        out = ', '.join(str(s) for s in sequence[:-1])
         if len(sequence) != 2:
             out += ','   # oxford comma
         out += ' '
@@ -41,6 +42,7 @@ def comma_list(sequence, article=''):
         out += str(sequence[-1])
         return out
 
+
 def comma_or(sequence):
     return comma_list(sequence, 'or')
 
diff --git a/lib/spack/spack/util/web.py b/lib/spack/spack/util/web.py
index cac783a368..25f1e605d6 100644
--- a/lib/spack/spack/util/web.py
+++ b/lib/spack/spack/util/web.py
@@ -43,6 +43,7 @@ TIMEOUT = 10
 class LinkParser(HTMLParser):
     """This parser just takes an HTML page and strips out the hrefs on the
        links.  Good enough for a really simple spider. """
+
     def __init__(self):
         HTMLParser.__init__(self)
         self.links = []
diff --git a/lib/spack/spack/variant.py b/lib/spack/spack/variant.py
index ad875f5ef5..b2c1a73489 100644
--- a/lib/spack/spack/variant.py
+++ b/lib/spack/spack/variant.py
@@ -29,8 +29,10 @@ currently variants are just flags.
 
 """
 
+
 class Variant(object):
     """Represents a variant on a build.  Can be either on or off."""
+
     def __init__(self, default, description):
         self.default     = default
         self.description = str(description)
diff --git a/lib/spack/spack/version.py b/lib/spack/spack/version.py
index 6f6c83b3d8..e1311eb0d9 100644
--- a/lib/spack/spack/version.py
+++ b/lib/spack/spack/version.py
@@ -50,6 +50,8 @@ from functools import wraps
 
 from functools_backport import total_ordering
 
+__all__ = ['Version', 'VersionRange', 'VersionList', 'ver']
+
 # Valid version characters
 VALID_VERSION = r'[A-Za-z0-9_.-]'
 
@@ -346,8 +348,8 @@ class VersionRange(object):
 
         s, o = self, other
         if s.start != o.start:
-            return s.start is None or (o.start is not None and s.start < o.start)  # NOQA: ignore=E501
-
+            return s.start is None or (
+                o.start is not None and s.start < o.start)
         return (s.end != o.end and
                 o.end is None or (s.end is not None and s.end < o.end))
 
diff --git a/lib/spack/spack/yaml_version_check.py b/lib/spack/spack/yaml_version_check.py
index c2d084d6c3..2c5b511d7f 100644
--- a/lib/spack/spack/yaml_version_check.py
+++ b/lib/spack/spack/yaml_version_check.py
@@ -34,6 +34,7 @@ import spack.config
 def check_yaml_versions():
     check_compiler_yaml_version()
 
+
 def check_compiler_yaml_version():
     config_scopes = spack.config.config_scopes
     for scope in config_scopes.values():
@@ -46,7 +47,8 @@ def check_compiler_yaml_version():
         if data:
             compilers = data['compilers']
             if len(compilers) > 0:
-                if (not isinstance(compilers, list)) or 'operating_system' not in compilers[0]['compiler']:
+                if (not isinstance(compilers, list) or
+                    'operating_system' not in compilers[0]['compiler']):
                     new_file = os.path.join(scope.path, '_old_compilers.yaml')
                     tty.warn('%s in out of date compilers format. '
                              'Moved to %s. Spack automatically generate '