matplotlib/matplotlib — pull request #2446 by mdboom (2013-09-20 16:14:15+00:00)
Title: Don't set use_2to3 unless we have to.

This is a minor point. If the user has an old version of distribute installed (such as the 0.6.11c that ships with OS-X Mountain Lion) it doesn't have the use_2to3 flag. This results in a Warning about an unknown keyword argument. It's not needed on Python 2 anyway, so it's easiest to just not include it on Python 2.

Note that this is irrelevant for master, where 2to3 is no longer used.