This is a working (and tested) implementation of serving Git repositories over HTTP in Phabricator. It uses git-http-backend, passing through the appropriate environment variables and parsing the response.

There's still some missing parts, such as drawing the repository folder from actual Phabricator data, and allowing a user to configure the location of git-http-backend from Phabricator config.

Created a Git repo at /home/james/git/test and cloned it with git clone http://phabricator.local/diffusion/git/ASD.