fix wheel packaging to properly require argparse on py26.2.0.1

1 files changed, 28 insertions, 5 deletions

diff --git a/setup.py b/setup.py
index 960cbed..726d675 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,5 @@
 import sys
-from setuptools import setup
+import setuptools
 from setuptools.command.test import test as TestCommand
 
 
@@ -15,18 +15,40 @@ class Tox(TestCommand):
         import tox
         tox.cmdline(self.test_args)
 
+def has_environment_marker_support():
+    """
+    Tests that setuptools has support for PEP-426 environment marker support.
+
+    The first known release to support it is 0.7 (and the earliest on PyPI seems to be 0.7.2
+    so we're using that), see: http://pythonhosted.org/setuptools/history.html#id142
+
+    References:
+
+    * https://wheel.readthedocs.org/en/latest/index.html#defining-conditional-dependencies
+    * https://www.python.org/dev/peps/pep-0426/#environment-markers
+    """
+    import pkg_resources
+    try:
+        return pkg_resources.parse_version(setuptools.__version__) >= pkg_resources.parse_version('0.7.2')
+    except Exception as exc:
+        sys.stderr.write("Could not test setuptool's version: %s\n" % exc)
+        return False
 
 def main():
     version = sys.version_info[:2]
     install_requires = ['virtualenv>=1.11.2', 'py>=1.4.17', 'pluggy>=0.3.0,<0.4.0']
-    if version < (2, 7):
-        install_requires += ['argparse']
-    setup(
+    extras_require = {}
+    if has_environment_marker_support():
+        extras_require[':python_version=="2.6"'] = ['argparse']
+    else:
+        if version < (2, 7):
+            install_requires += ['argparse']
+    setuptools.setup(
         name='tox',
         description='virtualenv-based automation of test activities',
         long_description=open("README.rst").read(),
         url='http://tox.testrun.org/',
-        version='2.0.0',
+        version='2.0.1',
         license='http://opensource.org/licenses/MIT',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],
         author='holger krekel',
@@ -38,6 +60,7 @@ def main():
         tests_require=['tox'],
         cmdclass={"test": Tox},
         install_requires=install_requires,
+        extras_require=extras_require,
         classifiers=[
             'Development Status :: 5 - Production/Stable',
             'Intended Audience :: Developers',