Comment 14 for bug 1274135

I just hit with this bug when using tox 1.7.1. I get the following error:

Traceback (most recent call last):
  File "/usr/local/bin/tox", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 2603, in <module>
    working_set.require(__requires__)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 666, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 565, in resolve
    raise DistributionNotFound(req) # XXX put more info here
pkg_resources.DistributionNotFound: virtualenv>=1.11.2