Virtualenv being ignored by setuptools/Distribute/easy_install
This one couldn’t be simpler, but it’s worth noting all the same. I’ve just experienced a situation where a virtualenv was being completely ignored by all tools even though it was absolutely activated via source bin/activate.
The answer was to blow away the lib directory within the virtualenv and blow away the local Python interpreter at bin/python and re-create the virtualenv. After deactivating and re-activating, everything works correctly again.
I guess something in the environment (or env variables) got messed up. Who knows; it works now.