pypa/pip — pull request #1828 by remram44 (2014-05-21 21:57:17+00:00)
Title: Catches BadCommand in get_src_requirement()

This catches the BadCommand that get raised by vcs modules when the VCS
software is not installed or not in the PATH. In this case, we behave as
if the .git, .svn or .hg folder hadn't been found at all (but with the
correct warning).