I have a tox.ini like this [tox] skipsdist = True envlist = begin,py35,py36,end [testenv] commands = pip install -e git+ssh://git@bitbucket.org/org/repo#egg=repo[server] and I get the error Could not detect requirement name for 'git+ssh://git@bitbucket.org/org/repo.git', please specify one with #egg=your_package_name It looks very much as if the # is treated as a comment. Is that the case? How can I escape it? What I tried \# : The \ is recognized, but not the rest - so it is not an escape character Quoting the whole string: ERROR: InvocationError: could not find executable 'pip install -e git