https://fedoraproject.org/wiki/Packaging:Python#Building_more_than_once

Ref:"One way that's currently very common is for the build scripts to create either a python2 or python3 module based on which interpreter is used to run the setup.py script. (The python-setuptools package is currently built this way)."

Well its url points to

http://cvs.fedoraproject.org/viewvc/rpms/python-setuptools/devel/python-setuptools.spec?revision=1.31&view=markup

well I think it should be changed to

pkgs.fedoraproject.org/cgit/python-setuptools.git/tree/python-setuptools.spec