remove wildcards from make spack core and packages

- This removes all wildcard imports EXCEPT `from spack import *` in packages

76 files changed, 195 insertions, 129 deletions

diff --git a/lib/spack/llnl/util/link_tree.py b/lib/spack/llnl/util/link_tree.py
index 6f6dabe430..49ee03c1ca 100644
--- a/lib/spack/llnl/util/link_tree.py
+++ b/lib/spack/llnl/util/link_tree.py
@@ -26,7 +26,8 @@
 
 import os
 import shutil
-from llnl.util.filesystem import *
+
+from llnl.util.filesystem import traverse_tree, mkdirp, touch
 
 __all__ = ['LinkTree']
 
diff --git a/lib/spack/llnl/util/tty/__init__.py b/lib/spack/llnl/util/tty/__init__.py
index 9a0f1c8438..ac51d201aa 100644
--- a/lib/spack/llnl/util/tty/__init__.py
+++ b/lib/spack/llnl/util/tty/__init__.py
@@ -32,7 +32,7 @@ import traceback
 from six import StringIO
 from six.moves import input
 
-from llnl.util.tty.color import *
+from llnl.util.tty.color import cprint, cwrite, cescape, clen
 
 _debug = False
 _verbose = False
diff --git a/lib/spack/spack/__init__.py b/lib/spack/spack/__init__.py
index 19590b6790..f7fa9ca836 100644
--- a/lib/spack/spack/__init__.py
+++ b/lib/spack/spack/__init__.py
@@ -90,7 +90,7 @@ from spack.abi import ABI
 from spack.concretize import DefaultConcretizer
 from spack.version import Version
 from spack.util.path import canonicalize_path
-
+from spack.package_prefs import PackageTesting
 
 #-----------------------------------------------------------------------------
 # Initialize various data structures & objects at the core of Spack.
@@ -158,7 +158,8 @@ dirty = _config.get('dirty', False)
 build_jobs = _config.get('build_jobs', multiprocessing.cpu_count())
 
 
-package_testing = spack.package_prefs.PackageTesting()
+# Needed for test dependencies
+package_testing = PackageTesting()
 
 
 #-----------------------------------------------------------------------------
diff --git a/lib/spack/spack/build_environment.py b/lib/spack/spack/build_environment.py
index f7cee015b6..cc03374769 100644
--- a/lib/spack/spack/build_environment.py
+++ b/lib/spack/spack/build_environment.py
@@ -62,15 +62,15 @@ from six import StringIO
 
 import llnl.util.tty as tty
 from llnl.util.tty.color import colorize
-from llnl.util.filesystem import *
+from llnl.util.filesystem import join_path, mkdirp, install, install_tree
 
 import spack
 import spack.store
 from spack.environment import EnvironmentModifications, validate
-from spack.util.environment import *
+from spack.util.environment import env_flag, filter_system_paths, get_path
 from spack.util.executable import Executable
 from spack.util.module_cmd import load_module, get_path_from_module
-from spack.util.log_parse import *
+from spack.util.log_parse import parse_log_events, make_log_context
 
 
 #
diff --git a/lib/spack/spack/build_systems/autotools.py b/lib/spack/spack/build_systems/autotools.py
index b78d3ed026..90ff8540bd 100644
--- a/lib/spack/spack/build_systems/autotools.py
+++ b/lib/spack/spack/build_systems/autotools.py
@@ -27,8 +27,7 @@ import inspect
 import os
 import os.path
 import shutil
-from os import stat
-from stat import *
+import stat
 from subprocess import PIPE
 from subprocess import check_call
 
@@ -153,7 +152,7 @@ class AutotoolsPackage(PackageBase):
         if config_guess is not None:
             try:
                 check_call([config_guess], stdout=PIPE, stderr=PIPE)
-                mod = stat(my_config_guess).st_mode & 0o777 | S_IWUSR
+                mod = os.stat(my_config_guess).st_mode & 0o777 | stat.S_IWUSR
                 os.chmod(my_config_guess, mod)
                 shutil.copyfile(config_guess, my_config_guess)
                 return
diff --git a/lib/spack/spack/cmd/__init__.py b/lib/spack/spack/cmd/__init__.py
index f1e36c2377..3f4f15c44b 100644
--- a/lib/spack/spack/cmd/__init__.py
+++ b/lib/spack/spack/cmd/__init__.py
@@ -29,9 +29,9 @@ import re
 import sys
 
 import llnl.util.tty as tty
-from llnl.util.lang import *
-from llnl.util.tty.colify import *
-from llnl.util.tty.color import *
+from llnl.util.lang import attr_setdefault, index_by
+from llnl.util.tty.colify import colify
+from llnl.util.tty.color import colorize
 from llnl.util.filesystem import working_dir
 
 import spack
diff --git a/lib/spack/spack/cmd/build.py b/lib/spack/spack/cmd/build.py
index 760aa5e339..70507f79e3 100644
--- a/lib/spack/spack/cmd/build.py
+++ b/lib/spack/spack/cmd/build.py
@@ -24,7 +24,13 @@
 ##############################################################################
 import spack.cmd.configure as cfg
 
-from spack import *
+from spack.build_systems.autotools import AutotoolsPackage
+from spack.build_systems.cmake import CMakePackage
+from spack.build_systems.qmake import QMakePackage
+from spack.build_systems.scons import SConsPackage
+from spack.build_systems.waf import WafPackage
+from spack.build_systems.python import PythonPackage
+from spack.build_systems.perl import PerlPackage
 
 description = 'stops at build stage when installing a package, if possible'
 section = "build"
diff --git a/lib/spack/spack/cmd/checksum.py b/lib/spack/spack/cmd/checksum.py
index e19eb540a8..bbdd9b0d82 100644
--- a/lib/spack/spack/cmd/checksum.py
+++ b/lib/spack/spack/cmd/checksum.py
@@ -31,8 +31,8 @@ import spack
 import spack.cmd
 import spack.util.crypto
 import spack.util.web
-from spack.util.naming import *
-from spack.version import *
+from spack.util.naming import valid_fully_qualified_module_name
+from spack.version import ver, Version
 
 description = "checksum available versions of a package"
 section = "packaging"
diff --git a/lib/spack/spack/cmd/configure.py b/lib/spack/spack/cmd/configure.py
index 795340630e..a85c035f38 100644
--- a/lib/spack/spack/cmd/configure.py
+++ b/lib/spack/spack/cmd/configure.py
@@ -28,7 +28,12 @@ import llnl.util.tty as tty
 import spack.cmd
 import spack.cmd.install as inst
 
-from spack import *
+from spack.build_systems.autotools import AutotoolsPackage
+from spack.build_systems.cmake import CMakePackage
+from spack.build_systems.qmake import QMakePackage
+from spack.build_systems.waf import WafPackage
+from spack.build_systems.perl import PerlPackage
+from spack.build_systems.intel import IntelPackage
 
 description = 'stage and configure a package but do not install'
 section = "build"
diff --git a/lib/spack/spack/cmd/create.py b/lib/spack/spack/cmd/create.py
index fd755facac..d38f11f63b 100644
--- a/lib/spack/spack/cmd/create.py
+++ b/lib/spack/spack/cmd/create.py
@@ -35,8 +35,10 @@ from llnl.util.filesystem import mkdirp
 from spack.repository import Repo
 from spack.spec import Spec
 from spack.util.executable import which
-from spack.util.naming import *
-from spack.url import *
+from spack.util.naming import mod_to_class
+from spack.util.naming import simplify_name, valid_fully_qualified_module_name
+from spack.url import UndetectableNameError, UndetectableVersionError
+from spack.url import parse_name, parse_version
 
 description = "create a new package file"
 section = "packaging"
diff --git a/lib/spack/spack/cmd/fetch.py b/lib/spack/spack/cmd/fetch.py
index 9df5f81404..7394903bfb 100644
--- a/lib/spack/spack/cmd/fetch.py
+++ b/lib/spack/spack/cmd/fetch.py
@@ -24,6 +24,8 @@
 ##############################################################################
 import argparse
 
+import llnl.util.tty as tty
+
 import spack
 import spack.cmd
 
diff --git a/lib/spack/spack/cmd/flake8.py b/lib/spack/spack/cmd/flake8.py
index 01e642235d..53eea0b995 100644
--- a/lib/spack/spack/cmd/flake8.py
+++ b/lib/spack/spack/cmd/flake8.py
@@ -31,10 +31,10 @@ import shutil
 import tempfile
 import argparse
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, mkdirp
 
 import spack
-from spack.util.executable import *
+from spack.util.executable import which
 
 
 description = "runs source code style checks on Spack. requires flake8"
diff --git a/lib/spack/spack/cmd/graph.py b/lib/spack/spack/cmd/graph.py
index e17d33f8b4..707e70dd61 100644
--- a/lib/spack/spack/cmd/graph.py
+++ b/lib/spack/spack/cmd/graph.py
@@ -30,9 +30,8 @@ import llnl.util.tty as tty
 import spack
 import spack.cmd
 import spack.store
-from spack.spec import *
-from spack.dependency import *
-from spack.graph import *
+from spack.dependency import all_deptypes, canonical_deptype
+from spack.graph import graph_dot, graph_ascii
 
 description = "generate graphs of package dependency relationships"
 section = "basic"
diff --git a/lib/spack/spack/cmd/help.py b/lib/spack/spack/cmd/help.py
index 0af5b471cd..f459134d24 100644
--- a/lib/spack/spack/cmd/help.py
+++ b/lib/spack/spack/cmd/help.py
@@ -23,7 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import sys
-from llnl.util.tty import colorize
+from llnl.util.tty.color import colorize
 
 description = "get help on spack and its commands"
 section = "help"
diff --git a/lib/spack/spack/cmd/info.py b/lib/spack/spack/cmd/info.py
index b3b95aa3df..0a54990b14 100644
--- a/lib/spack/spack/cmd/info.py
+++ b/lib/spack/spack/cmd/info.py
@@ -28,7 +28,7 @@ import textwrap
 
 from six.moves import zip_longest
 
-from llnl.util.tty.colify import *
+from llnl.util.tty.colify import colify
 
 import llnl.util.tty.color as color
 import spack
diff --git a/lib/spack/spack/cmd/pkg.py b/lib/spack/spack/cmd/pkg.py
index 8cd6534724..d9d451a3a6 100644
--- a/lib/spack/spack/cmd/pkg.py
+++ b/lib/spack/spack/cmd/pkg.py
@@ -32,7 +32,7 @@ from llnl.util.tty.colify import colify
 from llnl.util.filesystem import working_dir
 
 import spack
-from spack.util.executable import *
+from spack.util.executable import which
 from spack.cmd import spack_is_git_repo
 
 description = "query packages associated with particular git revisions"
diff --git a/lib/spack/spack/cmd/repo.py b/lib/spack/spack/cmd/repo.py
index ac0ae32c92..b51bab55d8 100644
--- a/lib/spack/spack/cmd/repo.py
+++ b/lib/spack/spack/cmd/repo.py
@@ -30,7 +30,7 @@ import llnl.util.tty as tty
 
 import spack.spec
 import spack.config
-from spack.repository import *
+from spack.repository import Repo, create_repo, canonicalize_path, RepoError
 
 description = "manage package source repositories"
 section = "config"
diff --git a/lib/spack/spack/cmd/test.py b/lib/spack/spack/cmd/test.py
index 54970f1ea2..abff6c7840 100644
--- a/lib/spack/spack/cmd/test.py
+++ b/lib/spack/spack/cmd/test.py
@@ -31,7 +31,7 @@ import argparse
 import pytest
 from six import StringIO
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir
 from llnl.util.tty.colify import colify
 
 import spack
diff --git a/lib/spack/spack/cmd/url.py b/lib/spack/spack/cmd/url.py
index e4419a5252..c4fae3dd21 100644
--- a/lib/spack/spack/cmd/url.py
+++ b/lib/spack/spack/cmd/url.py
@@ -29,7 +29,11 @@ from collections import defaultdict
 import spack
 
 from llnl.util import tty
-from spack.url import *
+from spack.url import parse_version_offset, parse_name_offset
+from spack.url import parse_name, parse_version, color_url
+from spack.url import substitute_version, substitution_offsets
+from spack.url import UndetectableNameError, UndetectableVersionError
+from spack.url import UrlParseError
 from spack.util.web import find_versions_of_archive
 from spack.util.naming import simplify_name
 
diff --git a/lib/spack/spack/compiler.py b/lib/spack/spack/compiler.py
index 362013436c..a16120aaa5 100644
--- a/lib/spack/spack/compiler.py
+++ b/lib/spack/spack/compiler.py
@@ -33,7 +33,7 @@ import spack.error
 import spack.spec
 import spack.architecture
 from spack.util.multiproc import parmap
-from spack.util.executable import *
+from spack.util.executable import Executable, ProcessError
 from spack.util.environment import get_path
 
 __all__ = ['Compiler', 'get_compiler_version']
diff --git a/lib/spack/spack/compilers/cce.py b/lib/spack/spack/compilers/cce.py
index 038d9dfe5a..0af52edec4 100644
--- a/lib/spack/spack/compilers/cce.py
+++ b/lib/spack/spack/compilers/cce.py
@@ -22,7 +22,7 @@
 # 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.compiler import *
+from spack.compiler import Compiler, get_compiler_version
 
 
 class Cce(Compiler):
diff --git a/lib/spack/spack/compilers/clang.py b/lib/spack/spack/compilers/clang.py
index b4caad7484..5a88897b68 100644
--- a/lib/spack/spack/compilers/clang.py
+++ b/lib/spack/spack/compilers/clang.py
@@ -25,13 +25,14 @@
 import re
 import os
 import sys
-import spack
-import spack.compiler as cpr
-from spack.compiler import *
-from spack.util.executable import *
+from shutil import copytree, ignore_patterns
+
 import llnl.util.tty as tty
+
+import spack
+from spack.compiler import Compiler, _version_cache
+from spack.util.executable import Executable
 from spack.version import ver
-from shutil import copytree, ignore_patterns
 
 
 class Clang(Compiler):
@@ -138,7 +139,7 @@ class Clang(Compiler):
             Target: x86_64-apple-darwin15.2.0
             Thread model: posix
         """
-        if comp not in cpr._version_cache:
+        if comp not in _version_cache:
             compiler = Executable(comp)
             output = compiler('--version', output=str, error=str)
 
@@ -153,9 +154,9 @@ class Clang(Compiler):
                 if match:
                     ver = match.group(1)
 
-            cpr._version_cache[comp] = ver
+            _version_cache[comp] = ver
 
-        return cpr._version_cache[comp]
+        return _version_cache[comp]
 
     def _find_full_path(self, path):
         basename = os.path.basename(path)
diff --git a/lib/spack/spack/compilers/gcc.py b/lib/spack/spack/compilers/gcc.py
index 70501b447f..c302db5c37 100644
--- a/lib/spack/spack/compilers/gcc.py
+++ b/lib/spack/spack/compilers/gcc.py
@@ -23,7 +23,9 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import llnl.util.tty as tty
-from spack.compiler import *
+
+import spack
+from spack.compiler import Compiler, get_compiler_version
 from spack.version import ver
 
 
diff --git a/lib/spack/spack/compilers/intel.py b/lib/spack/spack/compilers/intel.py
index 1959c9a661..f53ff2d3f1 100644
--- a/lib/spack/spack/compilers/intel.py
+++ b/lib/spack/spack/compilers/intel.py
@@ -22,8 +22,9 @@
 # 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.compiler import *
 import llnl.util.tty as tty
+
+from spack.compiler import Compiler, get_compiler_version
 from spack.version import ver
 
 
diff --git a/lib/spack/spack/compilers/nag.py b/lib/spack/spack/compilers/nag.py
index 0b568da8ed..4551917b20 100644
--- a/lib/spack/spack/compilers/nag.py
+++ b/lib/spack/spack/compilers/nag.py
@@ -22,7 +22,7 @@
 # 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.compiler import *
+from spack.compiler import Compiler, get_compiler_version
 
 
 class Nag(Compiler):
diff --git a/lib/spack/spack/compilers/pgi.py b/lib/spack/spack/compilers/pgi.py
index 9f0c6ce685..2ae3e78a59 100644
--- a/lib/spack/spack/compilers/pgi.py
+++ b/lib/spack/spack/compilers/pgi.py
@@ -22,7 +22,7 @@
 # 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.compiler import *
+from spack.compiler import Compiler, get_compiler_version
 
 
 class Pgi(Compiler):
diff --git a/lib/spack/spack/compilers/xl.py b/lib/spack/spack/compilers/xl.py
index 1a4df820f6..2ee39eb9c8 100644
--- a/lib/spack/spack/compilers/xl.py
+++ b/lib/spack/spack/compilers/xl.py
@@ -22,8 +22,9 @@
 # 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.compiler import *
 import llnl.util.tty as tty
+
+from spack.compiler import Compiler, get_compiler_version
 from spack.version import ver
 
 
diff --git a/lib/spack/spack/compilers/xl_r.py b/lib/spack/spack/compilers/xl_r.py
index dd6dc91aae..df4e7dfb54 100644
--- a/lib/spack/spack/compilers/xl_r.py
+++ b/lib/spack/spack/compilers/xl_r.py
@@ -23,8 +23,9 @@
 # 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.compiler import *
 import llnl.util.tty as tty
+
+from spack.compiler import Compiler, get_compiler_version
 from spack.version import ver
 
 
diff --git a/lib/spack/spack/concretize.py b/lib/spack/spack/concretize.py
index bcbe1b74b8..a510d142d9 100644
--- a/lib/spack/spack/concretize.py
+++ b/lib/spack/spack/concretize.py
@@ -34,17 +34,17 @@ TODO: make this customizable and allow users to configure
       concretization  policies.
 """
 from __future__ import print_function
-from six import iteritems
-from spack.version import *
 from itertools import chain
 from functools_backport import reverse_order
+from six import iteritems
 
 import spack
 import spack.spec
 import spack.compilers
 import spack.architecture
 import spack.error
-from spack.package_prefs import *
+from spack.version import ver, Version, VersionList, VersionRange
+from spack.package_prefs import PackagePrefs, spec_externals, is_spec_buildable
 
 
 class DefaultConcretizer(object):
@@ -65,7 +65,8 @@ class DefaultConcretizer(object):
         if spec.virtual:
             candidates = spack.repo.providers_for(spec)
             if not candidates:
-                raise UnsatisfiableProviderSpecError(candidates[0], spec)
+                raise spack.spec.UnsatisfiableProviderSpecError(
+                    candidates[0], spec)
 
             # Find nearest spec in the DAG (up then down) that has prefs.
             spec_w_prefs = find_spec(
diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
index 2458fb412d..46e8a5ae2e 100644
--- a/lib/spack/spack/database.py
+++ b/lib/spack/spack/database.py
@@ -49,8 +49,8 @@ from six import iteritems
 from yaml.error import MarkedYAMLError, YAMLError
 
 import llnl.util.tty as tty
-from llnl.util.filesystem import *
-from llnl.util.lock import *
+from llnl.util.filesystem import join_path, mkdirp
+from llnl.util.lock import Lock, WriteTransaction, ReadTransaction
 
 import spack.store
 import spack.repository
diff --git a/lib/spack/spack/directives.py b/lib/spack/spack/directives.py
index e294ac15d1..5dc6eaea4e 100644
--- a/lib/spack/spack/directives.py
+++ b/lib/spack/spack/directives.py
@@ -60,7 +60,7 @@ import spack
 import spack.error
 import spack.spec
 import spack.url
-from spack.dependency import *
+from spack.dependency import Dependency, default_deptype, canonical_deptype
 from spack.fetch_strategy import from_kwargs
 from spack.patch import Patch
 from spack.resource import Resource
diff --git a/lib/spack/spack/fetch_strategy.py b/lib/spack/spack/fetch_strategy.py
index 867d73d0a3..dc405f63d8 100644
--- a/lib/spack/spack/fetch_strategy.py
+++ b/lib/spack/spack/fetch_strategy.py
@@ -46,17 +46,17 @@ import re
 import shutil
 import copy
 from functools import wraps
-from six import string_types
-from six import with_metaclass
+from six import string_types, with_metaclass
 
 import llnl.util.tty as tty
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, mkdirp, join_path
+
 import spack
 import spack.error
 import spack.util.crypto as crypto
 import spack.util.pattern as pattern
-from spack.util.executable import *
-from spack.util.string import *
+from spack.util.executable import which
+from spack.util.string import comma_or
 from spack.version import Version, ver
 from spack.util.compression import decompressor_for, extension
 
diff --git a/lib/spack/spack/file_cache.py b/lib/spack/spack/file_cache.py
index 1f21531131..57e66e53b9 100644
--- a/lib/spack/spack/file_cache.py
+++ b/lib/spack/spack/file_cache.py
@@ -25,8 +25,8 @@
 import os
 import shutil
 
-from llnl.util.filesystem import *
-from llnl.util.lock import *
+from llnl.util.filesystem import mkdirp, join_path
+from llnl.util.lock import Lock, ReadTransaction, WriteTransaction
 
 from spack.error import SpackError
 
diff --git a/lib/spack/spack/graph.py b/lib/spack/spack/graph.py
index 994a0297b6..c059dfef65 100644
--- a/lib/spack/spack/graph.py
+++ b/lib/spack/spack/graph.py
@@ -61,15 +61,16 @@ Note that ``graph_ascii`` assumes a single spec while ``graph_dot``
 can take a number of specs as input.
 
 """
+import sys
 
-from heapq import *
+from heapq import heapify, heappop, heappush
 from six import iteritems
 
-from llnl.util.lang import *
-from llnl.util.tty.color import *
+from llnl.util.tty.color import ColorStream
+
+from spack.spec import Spec
+from spack.dependency import all_deptypes, canonical_deptype
 
-from spack.spec import *
-from spack.dependency import *
 
 __all__ = ['topological_sort', 'graph_ascii', 'AsciiGraph', 'graph_dot']
 
diff --git a/lib/spack/spack/hooks/case_consistency.py b/lib/spack/spack/hooks/case_consistency.py
index b76408e66e..e2d6c68ea1 100644
--- a/lib/spack/spack/hooks/case_consistency.py
+++ b/lib/spack/spack/hooks/case_consistency.py
@@ -28,11 +28,11 @@ import os
 import re
 import platform
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir
 
 import spack
 from spack.cmd import spack_is_git_repo
-from spack.util.executable import *
+from spack.util.executable import which, ProcessError
 
 
 def pre_run():
diff --git a/lib/spack/spack/main.py b/lib/spack/spack/main.py
index 2f542604d5..142d23d42a 100644
--- a/lib/spack/spack/main.py
+++ b/lib/spack/spack/main.py
@@ -38,7 +38,6 @@ from six import StringIO
 
 import llnl.util.tty as tty
 from llnl.util.tty.log import log_output
-from llnl.util.tty.color import *
 
 import spack
 import spack.cmd
diff --git a/lib/spack/spack/mirror.py b/lib/spack/spack/mirror.py
index 06bde4de1f..5b15f26ab2 100644
--- a/lib/spack/spack/mirror.py
+++ b/lib/spack/spack/mirror.py
@@ -33,14 +33,14 @@ to download packages directly from a mirror (e.g., on an intranet).
 import sys
 import os
 import llnl.util.tty as tty
-from llnl.util.filesystem import *
+from llnl.util.filesystem import mkdirp, join_path
 
 import spack
 import spack.error
 import spack.url as url
 import spack.fetch_strategy as fs
 from spack.spec import Spec
-from spack.version import *
+from spack.version import VersionList
 from spack.util.compression import allowed_archive
 
 
diff --git a/lib/spack/spack/multimethod.py b/lib/spack/spack/multimethod.py
index c439141683..67655e0e2f 100644
--- a/lib/spack/spack/multimethod.py
+++ b/lib/spack/spack/multimethod.py
@@ -45,7 +45,7 @@ so package authors should use their judgement.
 """
 import functools
 
-from llnl.util.lang import *
+from llnl.util.lang import caller_locals, get_calling_module_name
 
 import spack.architecture
 import spack.error
diff --git a/lib/spack/spack/operating_systems/cnl.py b/lib/spack/spack/operating_systems/cnl.py
index be6a9db60c..1f4ae3c5ab 100644
--- a/lib/spack/spack/operating_systems/cnl.py
+++ b/lib/spack/spack/operating_systems/cnl.py
@@ -24,10 +24,12 @@
 ##############################################################################
 import re
 
-from spack.architecture import OperatingSystem
+import llnl.util.tty as tty
+
 import spack.spec
-from spack.util.multiproc import parmap
 import spack.compilers
+from spack.architecture import OperatingSystem
+from spack.util.multiproc import parmap
 from spack.util.module_cmd import get_module_cmd
 
 
diff --git a/lib/spack/spack/operating_systems/mac_os.py b/lib/spack/spack/operating_systems/mac_os.py
index 52a26bc69a..a2f92e7685 100644
--- a/lib/spack/spack/operating_systems/mac_os.py
+++ b/lib/spack/spack/operating_systems/mac_os.py
@@ -23,8 +23,9 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import platform as py_platform
+
 from spack.architecture import OperatingSystem
-from spack.version import *
+from spack.version import Version
 
 
 # FIXME: store versions inside OperatingSystem as a Version instead of string
diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 92c4c6ed61..c4b8d53fa5 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -39,6 +39,7 @@ import functools
 import inspect
 import os
 import re
+import shutil
 import sys
 import textwrap
 import time
@@ -60,15 +61,16 @@ import spack.url
 import spack.util.web
 import spack.multimethod
 
-from llnl.util.filesystem import *
-from llnl.util.lang import *
+from llnl.util.filesystem import mkdirp, join_path, touch, ancestor
+from llnl.util.filesystem import working_dir, install_tree, install
+from llnl.util.lang import memoized
 from llnl.util.link_tree import LinkTree
 from llnl.util.tty.log import log_output
 from spack import directory_layout
 from spack.util.executable import which
 from spack.stage import Stage, ResourceStage, StageComposite
 from spack.util.environment import dump_environment
-from spack.version import *
+from spack.version import Version
 
 """Allowed URL schemes for spack packages."""
 _ALLOWED_URL_SCHEMES = ["http", "https", "ftp", "file", "git"]
diff --git a/lib/spack/spack/package_prefs.py b/lib/spack/spack/package_prefs.py
index 9a3059e748..dfe72c3163 100644
--- a/lib/spack/spack/package_prefs.py
+++ b/lib/spack/spack/package_prefs.py
@@ -30,7 +30,7 @@ from llnl.util.lang import classproperty
 import spack
 import spack.error
 from spack.util.path import canonicalize_path
-from spack.version import *
+from spack.version import VersionList
 
 
 _lesser_spec_types = {'compiler': spack.spec.CompilerSpec,
diff --git a/lib/spack/spack/package_test.py b/lib/spack/spack/package_test.py
index 32c6318a0d..3f15963461 100644
--- a/lib/spack/spack/package_test.py
+++ b/lib/spack/spack/package_test.py
@@ -22,8 +22,8 @@
 # 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 import *
 import os
+from spack.util.executable import which, Executable
 
 
 def compile_c_and_execute(source_file, include_flags, link_flags):
diff --git a/lib/spack/spack/parse.py b/lib/spack/spack/parse.py
index 45b3c2d417..56bf7dd2cb 100644
--- a/lib/spack/spack/parse.py
+++ b/lib/spack/spack/parse.py
@@ -24,6 +24,7 @@
 ##############################################################################
 import re
 import shlex
+import sys
 import itertools
 from six import string_types
 
diff --git a/lib/spack/spack/repository.py b/lib/spack/spack/repository.py
index ba33e24069..dedab9f51c 100644
--- a/lib/spack/spack/repository.py
+++ b/lib/spack/spack/repository.py
@@ -45,14 +45,15 @@ import yaml
 
 import llnl.util.lang
 import llnl.util.tty as tty
-from llnl.util.filesystem import *
+from llnl.util.filesystem import mkdirp, join_path, install
 
 import spack
 import spack.error
 import spack.spec
 from spack.provider_index import ProviderIndex
 from spack.util.path import canonicalize_path
-from spack.util.naming import *
+from spack.util.naming import NamespaceTrie, valid_module_name
+from spack.util.naming import mod_to_class, possible_spack_module_names
 
 #
 # Super-namespace for all packages.
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index dfc45850f7..3a4a5953b2 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -102,6 +102,7 @@ import ctypes
 import hashlib
 import itertools
 import os
+import re
 
 from operator import attrgetter
 from six import StringIO
@@ -109,8 +110,9 @@ from six import string_types
 from six import iteritems
 
 from llnl.util.filesystem import find_headers, find_libraries, is_exe
-from llnl.util.lang import *
-from llnl.util.tty.color import *
+from llnl.util.lang import key_ordering, HashableMap, ObjectWrapper, dedupe
+from llnl.util.lang import check_kwargs
+from llnl.util.tty.color import cwrite, colorize, cescape, get_color_when
 
 import spack
 import spack.architecture
@@ -121,7 +123,7 @@ import spack.store
 import spack.util.spack_json as sjson
 import spack.util.spack_yaml as syaml
 
-from spack.dependency import *
+from spack.dependency import Dependency, all_deptypes, canonical_deptype
 from spack.util.module_cmd import get_path_from_module, load_module
 from spack.error import SpecError, UnsatisfiableSpecError
 from spack.provider_index import ProviderIndex
@@ -129,9 +131,13 @@ from spack.util.crypto import prefix_bits
 from spack.util.executable import Executable
 from spack.util.prefix import Prefix
 from spack.util.spack_yaml import syaml_dict
-from spack.util.string import *
-from spack.variant import *
-from spack.version import *
+from spack.util.string import comma_or
+from spack.variant import MultiValuedVariant, AbstractVariant
+from spack.variant import BoolValuedVariant, substitute_abstract_variants
+from spack.variant import VariantMap, UnknownVariantError
+from spack.variant import DuplicateVariantError
+from spack.variant import UnsatisfiableVariantSpecError
+from spack.version import VersionList, VersionRange, Version, ver
 from yaml.error import MarkedYAMLError
 
 __all__ = [
diff --git a/lib/spack/spack/stage.py b/lib/spack/spack/stage.py
index 1d80eb9879..0fc75b1c08 100644
--- a/lib/spack/spack/stage.py
+++ b/lib/spack/spack/stage.py
@@ -35,14 +35,14 @@ from six.moves.urllib.parse import urljoin
 
 import llnl.util.tty as tty
 import llnl.util.lock
-from llnl.util.filesystem import *
+from llnl.util.filesystem import mkdirp, join_path, can_access
+from llnl.util.filesystem import remove_if_dead_link, remove_linked_tree
 
 import spack
 import spack.config
 import spack.error
 import spack.fetch_strategy as fs
 import spack.util.pattern as pattern
-from spack.version import *
 from spack.util.path import canonicalize_path
 from spack.util.crypto import prefix_bits, bit_length
 
diff --git a/lib/spack/spack/test/cc.py b/lib/spack/spack/test/cc.py
index 48f35873cb..9685ded121 100644
--- a/lib/spack/spack/test/cc.py
+++ b/lib/spack/spack/test/cc.py
@@ -31,9 +31,9 @@ import unittest
 import tempfile
 import shutil
 
-from llnl.util.filesystem import *
 import spack
-from spack.util.executable import *
+from llnl.util.filesystem import mkdirp, join_path
+from spack.util.executable import Executable
 
 # Complicated compiler test command
 test_command = [
diff --git a/lib/spack/spack/test/cmd/flake8.py b/lib/spack/spack/test/cmd/flake8.py
index b6433e95c9..52b8afc859 100644
--- a/lib/spack/spack/test/cmd/flake8.py
+++ b/lib/spack/spack/test/cmd/flake8.py
@@ -30,9 +30,9 @@ import sys
 from llnl.util.filesystem import FileFilter
 
 import spack
-from spack.cmd.flake8 import *
+from spack.cmd.flake8 import flake8, setup_parser, changed_files
 from spack.repository import Repo
-
+from spack.util.executable import which
 
 
 @pytest.fixture(scope='module')
diff --git a/lib/spack/spack/test/cmd/list.py b/lib/spack/spack/test/cmd/list.py
index d68f4ddc73..2cb80865c5 100644
--- a/lib/spack/spack/test/cmd/list.py
+++ b/lib/spack/spack/test/cmd/list.py
@@ -70,4 +70,4 @@ class TestListCommand(object):
 
         assert pkg_names
         assert 'cloverleaf3d' in pkg_names
-        assert 'hdf5' not in pkg_names
\ No newline at end of file
+        assert 'hdf5' not in pkg_names
diff --git a/lib/spack/spack/test/cmd/url.py b/lib/spack/spack/test/cmd/url.py
index 49b0732288..b3258a45d5 100644
--- a/lib/spack/spack/test/cmd/url.py
+++ b/lib/spack/spack/test/cmd/url.py
@@ -26,7 +26,8 @@ import re
 import pytest
 from spack.url import UndetectableVersionError
 from spack.main import SpackCommand
-from spack.cmd.url import *
+from spack.cmd.url import name_parsed_correctly, version_parsed_correctly
+from spack.cmd.url import url_summary
 
 url = SpackCommand('url')
 
diff --git a/lib/spack/spack/test/conftest.py b/lib/spack/spack/test/conftest.py
index 657d809dba..09aa8b8f86 100644
--- a/lib/spack/spack/test/conftest.py
+++ b/lib/spack/spack/test/conftest.py
@@ -44,9 +44,10 @@ import spack.repository
 import spack.stage
 import spack.util.executable
 import spack.util.pattern
-from spack.dependency import *
+from spack.dependency import Dependency
 from spack.package import PackageBase
-from spack.fetch_strategy import *
+from spack.fetch_strategy import FetchStrategyComposite, URLFetchStrategy
+from spack.fetch_strategy import FetchError
 from spack.spec import Spec
 from spack.version import Version
 
diff --git a/lib/spack/spack/test/database.py b/lib/spack/spack/test/database.py
index bc7354a4b4..98cc4a214a 100644
--- a/lib/spack/spack/test/database.py
+++ b/lib/spack/spack/test/database.py
@@ -27,14 +27,15 @@ These tests check the database is functioning properly,
 both in memory and in its file
 """
 import multiprocessing
-import os.path
-
+import os
 import pytest
+
+from llnl.util.tty.colify import colify
+
 import spack
 import spack.store
 from spack.test.conftest import MockPackageMultiRepo
 from spack.util.executable import Executable
-from llnl.util.tty.colify import colify
 
 
 def _print_ref_counts():
diff --git a/lib/spack/spack/test/directory_layout.py b/lib/spack/spack/test/directory_layout.py
index 0cfd796e06..efd1a69d84 100644
--- a/lib/spack/spack/test/directory_layout.py
+++ b/lib/spack/spack/test/directory_layout.py
@@ -26,11 +26,13 @@
 This test verifies that the Spack directory layout works properly.
 """
 import os
-
 import pytest
+
+from llnl.util.filesystem import join_path
+
 import spack
-from spack.directory_layout import (YamlDirectoryLayout,
-                                    InvalidDirectoryLayoutParametersError)
+from spack.directory_layout import YamlDirectoryLayout
+from spack.directory_layout import InvalidDirectoryLayoutParametersError
 from spack.repository import RepoPath
 from spack.spec import Spec
 
diff --git a/lib/spack/spack/test/git_fetch.py b/lib/spack/spack/test/git_fetch.py
index 1e17dbd6b2..e2edbc2b33 100644
--- a/lib/spack/spack/test/git_fetch.py
+++ b/lib/spack/spack/test/git_fetch.py
@@ -26,7 +26,7 @@ import os
 
 import pytest
 import spack
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, join_path, touch
 from spack.spec import Spec
 from spack.version import ver
 from spack.fetch_strategy import GitFetchStrategy
diff --git a/lib/spack/spack/test/hg_fetch.py b/lib/spack/spack/test/hg_fetch.py
index 410d7a4a42..629922cc0b 100644
--- a/lib/spack/spack/test/hg_fetch.py
+++ b/lib/spack/spack/test/hg_fetch.py
@@ -26,7 +26,7 @@ import os
 
 import pytest
 import spack
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, join_path, touch
 from spack.spec import Spec
 from spack.version import ver
 from spack.util.executable import which
diff --git a/lib/spack/spack/test/llnl/util/lang.py b/lib/spack/spack/test/llnl/util/lang.py
index 133ef6cc6c..9e92b0aa21 100644
--- a/lib/spack/spack/test/llnl/util/lang.py
+++ b/lib/spack/spack/test/llnl/util/lang.py
@@ -25,7 +25,7 @@
 import pytest
 from datetime import datetime, timedelta
 
-from llnl.util.lang import *
+from llnl.util.lang import pretty_date, match_predicate
 
 
 def test_pretty_date():
diff --git a/lib/spack/spack/test/llnl/util/link_tree.py b/lib/spack/spack/test/llnl/util/link_tree.py
index 64836a86f3..7088c10a77 100644
--- a/lib/spack/spack/test/llnl/util/link_tree.py
+++ b/lib/spack/spack/test/llnl/util/link_tree.py
@@ -25,7 +25,7 @@
 import os
 
 import pytest
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, mkdirp, touchp
 from llnl.util.link_tree import LinkTree
 from spack.stage import Stage
 
diff --git a/lib/spack/spack/test/llnl/util/lock.py b/lib/spack/spack/test/llnl/util/lock.py
index 208777ae51..4466d5999b 100644
--- a/lib/spack/spack/test/llnl/util/lock.py
+++ b/lib/spack/spack/test/llnl/util/lock.py
@@ -73,8 +73,8 @@ from multiprocessing import Process
 import pytest
 
 from llnl.util.filesystem import join_path, touch
-from llnl.util.lock import *
 from spack.util.multiproc import Barrier
+from llnl.util.lock import Lock, WriteTransaction, ReadTransaction, LockError
 
 
 #
diff --git a/lib/spack/spack/test/make_executable.py b/lib/spack/spack/test/make_executable.py
index f47bc1e6a3..cfc7f8ec60 100644
--- a/lib/spack/spack/test/make_executable.py
+++ b/lib/spack/spack/test/make_executable.py
@@ -32,7 +32,7 @@ import shutil
 import tempfile
 import unittest
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import join_path
 from spack.build_environment import MakeExecutable
 from spack.util.environment import path_put_first
 
diff --git a/lib/spack/spack/test/module_parsing.py b/lib/spack/spack/test/module_parsing.py
index 7483b66ebb..df79168d48 100644
--- a/lib/spack/spack/test/module_parsing.py
+++ b/lib/spack/spack/test/module_parsing.py
@@ -25,7 +25,11 @@
 import pytest
 import subprocess
 import os
-from spack.util.module_cmd import *
+from spack.util.module_cmd import get_path_from_module
+from spack.util.module_cmd import get_argument_from_module_line
+from spack.util.module_cmd import get_module_cmd_from_bash
+from spack.util.module_cmd import get_module_cmd, ModuleError
+
 
 typeset_func = subprocess.Popen('module avail',
                                 stdout=subprocess.PIPE,
diff --git a/lib/spack/spack/test/multimethod.py b/lib/spack/spack/test/multimethod.py
index 4f6dce1ea7..ae4b97cbed 100644
--- a/lib/spack/spack/test/multimethod.py
+++ b/lib/spack/spack/test/multimethod.py
@@ -25,8 +25,7 @@
 """Test for multi_method dispatch."""
 import spack
 import pytest
-from spack.multimethod import *
-from spack.version import *
+from spack.multimethod import NoSuchMethodError
 
 
 def test_no_version_match(builtin_mock):
diff --git a/lib/spack/spack/test/packages.py b/lib/spack/spack/test/packages.py
index 2fcac53201..4d82f273eb 100644
--- a/lib/spack/spack/test/packages.py
+++ b/lib/spack/spack/test/packages.py
@@ -28,7 +28,7 @@ import pytest
 from llnl.util.filesystem import join_path
 from spack.repository import Repo
 from spack.util.naming import mod_to_class
-from spack.spec import *
+from spack.spec import Spec
 
 
 @pytest.mark.usefixtures('config', 'builtin_mock')
diff --git a/lib/spack/spack/test/packaging.py b/lib/spack/spack/test/packaging.py
index de3de6b29c..29a0f0b69a 100644
--- a/lib/spack/spack/test/packaging.py
+++ b/lib/spack/spack/test/packaging.py
@@ -40,8 +40,11 @@ import spack.binary_distribution as bindist
 import spack.cmd.buildcache as buildcache
 from spack.spec import Spec
 from spack.fetch_strategy import URLFetchStrategy, FetchStrategyComposite
-from spack.relocate import *
 from spack.util.executable import ProcessError
+from spack.relocate import needs_binary_relocation, get_patchelf
+from spack.relocate import substitute_rpath, get_relative_rpaths
+from spack.relocate import macho_replace_paths, macho_make_paths_relative
+from spack.relocate import modify_macho_object, macho_get_paths
 
 
 @pytest.fixture(scope='function')
diff --git a/lib/spack/spack/test/sbang.py b/lib/spack/spack/test/sbang.py
index 09fcdab652..c6b3b465e8 100644
--- a/lib/spack/spack/test/sbang.py
+++ b/lib/spack/spack/test/sbang.py
@@ -32,10 +32,10 @@ import tempfile
 import shutil
 import filecmp
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import mkdirp
 
 import spack
-from spack.hooks.sbang import *
+from spack.hooks.sbang import shebang_too_long, filter_shebangs_in_directory
 from spack.util.executable import which
 
 
diff --git a/lib/spack/spack/test/spec_dag.py b/lib/spack/spack/test/spec_dag.py
index a45cb7a961..c85c48504f 100644
--- a/lib/spack/spack/test/spec_dag.py
+++ b/lib/spack/spack/test/spec_dag.py
@@ -31,7 +31,7 @@ import spack.architecture
 import spack.package
 
 from spack.spec import Spec
-from spack.dependency import *
+from spack.dependency import all_deptypes, Dependency, canonical_deptype
 from spack.test.conftest import MockPackage, MockPackageMultiRepo
 
 
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index e2219e3270..cb6fcc7775 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -25,8 +25,10 @@
 import spack.architecture
 import pytest
 
-from spack.spec import *
-from spack.variant import *
+from spack.spec import Spec, UnsatisfiableSpecError
+from spack.spec import substitute_abstract_variants, parse_anonymous_spec
+from spack.variant import InvalidVariantValueError
+from spack.variant import MultipleValuesInExclusiveVariantError
 
 
 def target_factory(spec_string, target_concrete):
diff --git a/lib/spack/spack/test/spec_syntax.py b/lib/spack/spack/test/spec_syntax.py
index cdae4bfda9..b56246d1fc 100644
--- a/lib/spack/spack/test/spec_syntax.py
+++ b/lib/spack/spack/test/spec_syntax.py
@@ -28,7 +28,12 @@ import shlex
 import spack
 import spack.spec as sp
 from spack.parse import Token
-from spack.spec import *
+from spack.spec import Spec, parse, parse_anonymous_spec
+from spack.spec import SpecParseError, RedundantSpecError
+from spack.spec import AmbiguousHashError, InvalidHashError, NoSuchHashError
+from spack.spec import DuplicateArchitectureError, DuplicateVariantError
+from spack.spec import DuplicateDependencyError, DuplicateCompilerSpecError
+
 
 # Sample output for a complex lexing.
 complex_lex = [Token(sp.ID, 'mvapich_foo'),
diff --git a/lib/spack/spack/test/svn_fetch.py b/lib/spack/spack/test/svn_fetch.py
index 304edc2828..35b2d786bb 100644
--- a/lib/spack/spack/test/svn_fetch.py
+++ b/lib/spack/spack/test/svn_fetch.py
@@ -26,7 +26,7 @@ import os
 
 import pytest
 import spack
-from llnl.util.filesystem import *
+from llnl.util.filesystem import join_path, touch, working_dir
 from spack.spec import Spec
 from spack.version import ver
 from spack.util.executable import which
diff --git a/lib/spack/spack/test/url_fetch.py b/lib/spack/spack/test/url_fetch.py
index 21d871173e..fba087dc99 100644
--- a/lib/spack/spack/test/url_fetch.py
+++ b/lib/spack/spack/test/url_fetch.py
@@ -25,7 +25,7 @@
 import os
 import pytest
 
-from llnl.util.filesystem import *
+from llnl.util.filesystem import working_dir, is_exe
 
 import spack
 from spack.spec import Spec
diff --git a/lib/spack/spack/test/url_parse.py b/lib/spack/spack/test/url_parse.py
index 3798221cef..4638071126 100644
--- a/lib/spack/spack/test/url_parse.py
+++ b/lib/spack/spack/test/url_parse.py
@@ -27,9 +27,13 @@ based on its URL.
 """
 
 import os
-
 import pytest
-from spack.url import *
+
+from spack.url import parse_name_offset, parse_version_offset
+from spack.url import parse_name_and_version, substitute_version
+from spack.url import strip_name_suffixes, strip_version_suffixes
+from spack.url import UndetectableVersionError
+from spack.version import Version
 
 
 @pytest.mark.parametrize('url,expected', [
diff --git a/lib/spack/spack/test/variant.py b/lib/spack/spack/test/variant.py
index b7117f02ce..9f6a429bda 100644
--- a/lib/spack/spack/test/variant.py
+++ b/lib/spack/spack/test/variant.py
@@ -26,7 +26,12 @@
 import pytest
 import numbers
 
-from spack.variant import *
+from spack.variant import Variant, SingleValuedVariant, VariantMap
+from spack.variant import MultiValuedVariant, BoolValuedVariant
+from spack.variant import UnsatisfiableVariantSpecError
+from spack.variant import InconsistentValidationError
+from spack.variant import MultipleValuesInExclusiveVariantError
+from spack.variant import InvalidVariantValueError, DuplicateVariantError
 
 
 class TestMultiValuedVariant(object):
diff --git a/lib/spack/spack/test/versions.py b/lib/spack/spack/test/versions.py
index 4298cdc2b0..48e88a6bb6 100644
--- a/lib/spack/spack/test/versions.py
+++ b/lib/spack/spack/test/versions.py
@@ -28,7 +28,7 @@ where it makes sense.
 """
 import pytest
 
-from spack.version import *
+from spack.version import Version, ver
 
 
 def assert_ver_lt(a, b):
diff --git a/lib/spack/spack/test/web.py b/lib/spack/spack/test/web.py
index 80a8cc036d..f47efc8dc6 100644
--- a/lib/spack/spack/test/web.py
+++ b/lib/spack/spack/test/web.py
@@ -27,7 +27,7 @@ import os
 
 import spack
 from spack.util.web import spider, find_versions_of_archive
-from spack.version import *
+from spack.version import ver
 
 
 web_data_path = os.path.join(spack.test_path, 'data', 'web')
diff --git a/lib/spack/spack/url.py b/lib/spack/spack/url.py
index 7c8024c986..41df8cc3a5 100644
--- a/lib/spack/spack/url.py
+++ b/lib/spack/spack/url.py
@@ -50,7 +50,7 @@ from six import StringIO
 from six.moves.urllib.parse import urlsplit, urlunsplit
 
 import llnl.util.tty as tty
-from llnl.util.tty.color import *
+from llnl.util.tty.color import colorize
 
 import spack.error
 import spack.util.compression as comp
diff --git a/lib/spack/spack/util/spack_yaml.py b/lib/spack/spack/util/spack_yaml.py
index f0a0f20856..8497ee6e4a 100644
--- a/lib/spack/spack/util/spack_yaml.py
+++ b/lib/spack/spack/util/spack_yaml.py
@@ -33,7 +33,7 @@
 """
 import yaml
 from yaml import Loader, Dumper
-from yaml.nodes import *
+from yaml.nodes import MappingNode, SequenceNode, ScalarNode
 from yaml.constructor import ConstructorError
 from ordereddict_backport import OrderedDict