Don't need it

versiontools_support.py

-# Copyright (C) 2012 Linaro Limited
-#
-# Author: Zygmunt Krynicki <zygmunt.krynicki@linaro.org>
-#
-# This file is part of versiontools.
-#
-# versiontools is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3
-# as published by the Free Software Foundation
-#
-# versiontools 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
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with versiontools.  If not, see <http://www.gnu.org/licenses/>.
-
-"""
-versiontools.versiontools_support
-=================================
-
-A small standalone module that allows any package to use versiontools.
-
-Typically you should copy this file verbatim into your source distribution.
-
-Historically versiontools was depending on a exotic feature of setuptools to
-work. Setuptools has so-called setup-time dependencies, that is modules that
-need to be downloaded and imported/interrogated for setup.py to run
-successfully. Versiontools supports this by installing a handler for the
-'version' keyword of the setup() function.
-
-This approach was always a little annoying as this setuptools feature is rather
-odd and very few other packages made any use of it. In the future the standard
-tools for python packaging (especially in python3 world) this feature may be
-removed or have equivalent thus rendering versiontools completely broken.
-
-Currently the biggest practical issue is the apparent inability to prevent
-setuptools from downloading packages designated as setup_requires. This is
-discussed in this pip issue: https://github.com/pypa/pip/issues/410
-
-To counter this issue I've redesigned versiontools to be a little smarter. The
-old mode stays as-is for compatibility. The new mode works differently, without
-the need for using setup_requires in your setup() call. Instead it requires
-each package that uses versiontools to ship a verbatim copy of this module and
-to import it in their setup.py script. This module helps setuptools find
-package version in the standard PKG-INFO file that is created for all source
-distributions. Remember that you only need this mode when you don't want to add
-a dependency on versiontools. This will still allow you to use versiontools (in
-a limited way) in your setup.py file.
-
-Technically this module defines an improved version of one of
-distutils.dist.DistributionMetadata class and monkey-patches distutils to use
-it. To retain backward compatibility the new feature is only active when a
-special version string is passed to the setup() call.
-"""
-
-__version__ = (1, 0, 0, "final", 0)
-
-import distutils.dist
-import distutils.errors
-
-
-class VersiontoolsEnchancedDistributionMetadata(distutils.dist.DistributionMetadata):
-    """
-    A subclass of distutils.dist.DistributionMetadata that uses versiontools
-
-    Typically you would not instantiate this class directly. It is constructed
-    by distutils.dist.Distribution.__init__() method. Since there is no other
-    way to do it, this module monkey-patches distutils to override the original
-    version of DistributionMetadata
-    """
-
-    # Reference to the original class. This is only required because distutils
-    # was created before the introduction of new-style classes to python.
-    __base = distutils.dist.DistributionMetadata
-
-    def get_version(self): 
-        """
-        Get distribution version.
-
-        This method is enhanced compared to original distutils implementation.
-        If the version string is set to a special value then instead of using
-        the actual value the real version is obtained by querying versiontools.
-
-        If versiontools package is not installed then the version is obtained
-        from the standard section of the ``PKG-INFO`` file. This file is
-        automatically created by any source distribution. This method is less
-        useful as it cannot take advantage of version control information that
-        is automatically loaded by versiontools. It has the advantage of not
-        requiring versiontools installation and that it does not depend on
-        ``setup_requires`` feature of ``setuptools``.
-        """
-        if (self.name is not None and self.version is not None
-            and self.version.startswith(":versiontools:")):
-            return (self.__get_live_version() or self.__get_frozen_version()
-                    or self.__fail_to_get_any_version())
-        else:
-            return self.__base.get_version(self)
-
-    def __get_live_version(self):
-        """
-        Get a live version string using versiontools
-        """
-        try:
-            import versiontools
-        except ImportError:
-            return None
-        else:
-            return str(versiontools.Version.from_expression(self.name))
-
-    def __get_frozen_version(self):
-        """
-        Get a fixed version string using an existing PKG-INFO file
-        """
-        try:
-            return self.__base("PKG-INFO").version
-        except IOError:
-            return None
-
-    def __fail_to_get_any_version(self):
-        """
-        Raise an informative exception
-        """
-        raise SystemExit(
-"""This package requires versiontools for development or testing.
-
-See http://versiontools.readthedocs.org/ for more information about
-what versiontools is and why it is useful.
-
-To install versiontools now please run:
-    $ pip install versiontools
-
-Note: versiontools works best when you have additional modules for
-integrating with your preferred version control system. Refer to
-the documentation for a full list of required modules.""")
-
-
-# If DistributionMetadata is not a subclass of
-# VersiontoolsEnhancedDistributionMetadata then monkey patch it. This should
-# prevent a (odd) case of multiple imports of this module.
-if not issubclass(
-    distutils.dist.DistributionMetadata,
-    VersiontoolsEnchancedDistributionMetadata):
-    distutils.dist.DistributionMetadata = VersiontoolsEnchancedDistributionMetadata