Properly ignore flake8 F811 redefinition errors (#3932)

* Properly ignore flake8 F811 redefinition errors
* Add unit tests for flake8 command
* Allow spack flake8 to work on systems with older git
* Skip flake8 unit tests for Python 2.6 and 3.3

5 files changed, 169 insertions, 6 deletions

diff --git a/var/spack/repos/builtin.mock/packages/boost/package.py b/var/spack/repos/builtin.mock/packages/boost/package.py
new file mode 100644
index 0000000000..5d86c4559f
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/boost/package.py
@@ -0,0 +1,83 @@
+##############################################################################
+# 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 import *
+
+
+class Boost(Package):
+    """Fake boost package."""
+
+    homepage = "http://www.boost.org"
+    url      = "http://downloads.sourceforge.net/project/boost/boost/1.63.0/boost_1_63_0.tar.bz2"
+
+    version('1.63.0', '1c837ecd990bb022d07e7aab32b09847')
+
+    default_install_libs = set(['atomic',
+                                'chrono',
+                                'date_time',
+                                'filesystem',
+                                'graph',
+                                'iostreams',
+                                'locale',
+                                'log',
+                                'math',
+                                'program_options',
+                                'random',
+                                'regex',
+                                'serialization',
+                                'signals',
+                                'system',
+                                'test',
+                                'thread',
+                                'timer',
+                                'wave'])
+
+    # mpi/python are not installed by default because they pull in many
+    # dependencies and/or because there is a great deal of customization
+    # possible (and it would be difficult to choose sensible defaults)
+    default_noinstall_libs = set(['mpi', 'python'])
+
+    all_libs = default_install_libs | default_noinstall_libs
+
+    for lib in all_libs:
+        variant(lib, default=(lib not in default_noinstall_libs),
+                description="Compile with {0} library".format(lib))
+
+    variant('debug', default=False,
+            description='Switch to the debug version of Boost')
+    variant('shared', default=True,
+            description="Additionally build shared libraries")
+    variant('multithreaded', default=True,
+            description="Build multi-threaded versions of libraries")
+    variant('singlethreaded', default=False,
+            description="Build single-threaded versions of libraries")
+    variant('icu', default=False,
+            description="Build with Unicode and ICU suport")
+    variant('graph', default=False,
+            description="Build the Boost Graph library")
+    variant('taggedlayout', default=False,
+            description="Augment library names with build options")
+
+    def install(self, spec, prefix):
+        pass
diff --git a/var/spack/repos/builtin.mock/packages/flake8/hyper-specific-patch-that-fixes-some-random-bug-that-probably-only-affects-one-user.patch b/var/spack/repos/builtin.mock/packages/flake8/hyper-specific-patch-that-fixes-some-random-bug-that-probably-only-affects-one-user.patch
new file mode 100644
index 0000000000..b8c9065e4b
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/flake8/hyper-specific-patch-that-fixes-some-random-bug-that-probably-only-affects-one-user.patch
@@ -0,0 +1 @@
+Fake patch
diff --git a/var/spack/repos/builtin.mock/packages/flake8/package.py b/var/spack/repos/builtin.mock/packages/flake8/package.py
new file mode 100644
index 0000000000..bd062d71bc
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/flake8/package.py
@@ -0,0 +1,79 @@
+##############################################################################
+# 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 import *
+
+
+class Flake8(Package):
+    """Package containing as many PEP 8 violations as possible.
+    All of these violations are exceptions that we allow in
+    package.py files."""
+
+    # Used to tell whether or not the package has been modified
+    state = 'unmodified'
+
+    # Make sure pre-existing noqa is not interfered with
+    blatant_violation = 'line-that-has-absolutely-no-execuse-for-being-over-79-characters'  # noqa
+    blatant_violation = 'line-that-has-absolutely-no-execuse-for-being-over-79-characters'  # noqa: E501
+
+    # Keywords exempt from line-length checks
+    homepage = '#####################################################################'
+    url      = '#####################################################################'
+    git      = '#####################################################################'
+    svn      = '#####################################################################'
+    hg       = '#####################################################################'
+    list_url = '#####################################################################'
+
+    # URL strings exempt from line-length checks
+    # http://########################################################################
+    # https://#######################################################################
+    # ftp://#########################################################################
+    # file://########################################################################
+
+    # Directives exempt from line-length checks
+    version('2.0', '0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef')
+    version('1.0', '0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef')
+
+    variant('super-awesome-feature',    default=True,  description='Enable super awesome feature')
+    variant('somewhat-awesome-feature', default=False, description='Enable somewhat awesome feature')
+
+    provides('lapack', when='@2.0+super-awesome-feature+somewhat-awesome-feature')
+
+    extends('python', ignore='bin/(why|does|every|package|that|depends|on|numpy|need|to|copy|f2py3?)')
+
+    depends_on('boost+atomic+chrono+date_time~debug+filesystem~graph~icu+iostreams+locale+log+math~mpi+multithreaded+program_options~python+random+regex+serialization+shared+signals~singlethreaded+system~taggedlayout+test+thread+timer+wave')
+
+    conflicts('+super-awesome-feature', when='%intel@16:17+somewhat-awesome-feature')
+
+    resource(name='Deez-Nuts', destination='White-House', placement='President', when='@2020', url='www.elect-deez-nuts.com')
+
+    patch('hyper-specific-patch-that-fixes-some-random-bug-that-probably-only-affects-one-user.patch', when='%gcc@3.2.2:3.2.3')
+
+    def install(self, spec, prefix):
+        pass
+
+    # '@when' decorated functions are exempt from redefinition errors
+    @when('@2.0')
+    def install(self, spec, prefix):
+        pass
diff --git a/var/spack/repos/builtin/packages/metis/package.py b/var/spack/repos/builtin/packages/metis/package.py
index c927c22a1b..454bb97037 100644
--- a/var/spack/repos/builtin/packages/metis/package.py
+++ b/var/spack/repos/builtin/packages/metis/package.py
@@ -84,7 +84,7 @@ class Metis(Package):
             filter_file('#define MAX_JBUFS 128', '#define MAX_JBUFS 24',
                         join_path(source_path, 'GKlib', 'error.c'))
 
-    @when('@:4')  # noqa: F811
+    @when('@:4')
     def install(self, spec, prefix):
         # Process library spec and options
         if any('+{0}'.format(v) in spec for v in ['gdb', 'int64', 'real64']):
@@ -175,7 +175,7 @@ class Metis(Package):
             Executable(test_bin('mesh2dual'))(test_graph('metis.mesh'))
             """
 
-    @when('@5:')  # noqa: F811
+    @when('@5:')
     def install(self, spec, prefix):
         source_directory = self.stage.source_path
         build_directory = join_path(source_directory, 'build')
diff --git a/var/spack/repos/builtin/packages/qt/package.py b/var/spack/repos/builtin/packages/qt/package.py
index b27bc3fe07..b9c7e1f5c3 100644
--- a/var/spack/repos/builtin/packages/qt/package.py
+++ b/var/spack/repos/builtin/packages/qt/package.py
@@ -251,7 +251,7 @@ class Qt(Package):
     # Don't disable all the database drivers, but should
     # really get them into spack at some point.
 
-    @when('@3')  # noqa: F811
+    @when('@3')
     def configure(self):
         # A user reported that this was necessary to link Qt3 on ubuntu.
         # However, if LD_LIBRARY_PATH is not set the qt build fails, check
@@ -268,7 +268,7 @@ class Qt(Package):
                   '-release',
                   '-fast')
 
-    @when('@4')  # noqa: F811
+    @when('@4')
     def configure(self):
         configure('-fast',
                   '-{0}gtkstyle'.format('' if '+gtk' in self.spec else 'no-'),
@@ -276,7 +276,7 @@ class Qt(Package):
                   '-arch', str(self.spec.architecture.target),
                   *self.common_config_args)
 
-    @when('@5.0:5.6')  # noqa: F811
+    @when('@5.0:5.6')
     def configure(self):
         webkit_args = [] if '+webkit' in self.spec else ['-skip', 'qtwebkit']
         configure('-no-eglfs',
@@ -284,7 +284,7 @@ class Qt(Package):
                   '-{0}gtkstyle'.format('' if '+gtk' in self.spec else 'no-'),
                   *(webkit_args + self.common_config_args))
 
-    @when('@5.7:')  # noqa: F811
+    @when('@5.7:')
     def configure(self):
         config_args = self.common_config_args