The branch you are looking at is an effort towards getting Firefox Share working with the Open Web Apps infrastructure.
To pull and run fx-share addon:
git clone https://github.com/mozilla/fx-share-addon cd fx-share-addon make pull make run
You can build an xpi:
You can run the tests:
If you want to run (using make run) in a specific profile:
OWA_PROFILE=/path/to/firefox/profile make run
Tests cannot be run in a specific profile.
You probably want a test firefox profile so open up the Profile Manager.
In the Mac:
In the profile manager, create a profile with the name
fxsharetest, then exit the profile manager.