robbyrussell/oh-my-zsh — pull request #2274 by benjaoming (2013-11-22 10:48:20+00:00)
Title: Throw an error message when $WORKON_HOME is not set

Took me a while to figure this one out, and I have a default installation of virtualenvwrapper -- this is a soft fix, just put an error message. But perhaps the fix should be to use the default value `~/.virtualenvs`.