Here's my file layout: <root> / |- setup.py | |- enum / |- __init__.py | |- py2_enum.py | |- py3_enum.py | |- test / |- test_enum.py | |- py2_test_enum.py | |- py3_test_enum.py __init__ and test_enum are both smart enough to pull in the correct code when imported. The issue I am having is this: --8<-------------------------------------------------------------- ethan@hydra:~$ sudo easy_install enum34 [sudo] password for ethan: Searching for enum34 Reading http://pypi.python.org/simple/enum34/ Best match: enum34 0.9 Downloading http://pypi.python.org/packages/source/e/enum34/enum34-0.9.zip#md5=4717b8c32... Processing enum34-0.9.zip Writing /tmp/easy_install-sB55B5/enum34-0.9/setup.cfg Running enum34-0.9/setup.py -q bdist_egg --dist-dir /tmp/easy_install-sB55B5/enum34-0.9/egg-dist-tmp-qUYAv5 SyntaxError: ('invalid syntax', ('build/bdist.linux-x86_64/egg/enum/py3_enum.py', 211, 43, ' def __call__(cls, value, names=None, *, module=None, type=None):\n')) SyntaxError: ('invalid syntax', ('build/bdist.linux-x86_64/egg/enum/test/py3_test_enum.py', 630, 47, ' class AutoNumberedEnum(Enum, metaclass=auto_enum):\n')) zip_safe flag not set; analyzing archive contents... SyntaxError: ('invalid syntax', ('/usr/local/lib/python2.7/dist-packages/enum34-0.9-py2.7.egg/enum/py3_enum.py', 211, 43, ' def __call__(cls, value, names=None, *, module=None, type=None):\n')) SyntaxError: ('invalid syntax', ('/usr/local/lib/python2.7/dist-packages/enum34-0.9-py2.7.egg/enum/test/py3_test_enum.py', 630, 47, ' class AutoNumberedEnum(Enum, metaclass=auto_enum):\n')) Adding enum34 0.9 to easy-install.pth file Installed /usr/local/lib/python2.7/dist-packages/enum34-0.9-py2.7.egg Processing dependencies for enum34 Finished processing dependencies for enum34 --8<-------------------------------------------------------------- distutils is trying to load the py3 versions, which of course fails on a py2 install. The package installs successfully anyway, but if I were a user I would be wondering if the install was trustworthy. It seems to me that I need to either have distutils only install the version appropriate files, or to not try to scan the version inappropriate files, but at this point I do not know how to do either. Any pointers would be greatly appreciated. -- ~Ethan~