Installing packages from pip is not just convenient, it’s also a requirement when working from a virtualenv. Unfortunately, there comes a time when installing a specific version of a package requires a little more finess–and often some mucking about on Github. While there are solutions to this dilemma, the cleanest and most concise one I’ve yet discovered is to modify a particular Github trick that’s documented both on Github and in a number of Python package repositories that are not presently available on PyPI:

pip install https://github.com/<username>/<package>/tarball/<tag, branch, or commit>

For example:

pip install https://github.com/surfly/gevent/tarball/1.0rc3

That’s it!