I've installed a library using the command

pip install git+git://github.com/mozilla/elasticutils.git

which installs it directly from a Github repository. This works fine and I want to have that dependency in my requirements.txt. I've looked at other tickets like this but that didn't solve my problem. If I put something like

-f git+git://github.com/mozilla/elasticutils.git
elasticutils==0.7.dev

in the requirements.txt file, a pip install -r requirements.txt results in the following output:

Downloading/unpacking elasticutils==0.7.dev (from -r requirements.txt (line 20))
  Could not find a version that satisfies the requirement elasticutils==0.7.dev (from -r requirements.txt (line 20)) (from versions: )
No distributions matching the version for elasticutils==0.7.dev (from -r requirements.txt (line 20))

The documentation of the requirements file does not mention links using the git+git protocol specifier, so maybe this is just not supported.

Does anybody have a solution for my problem?