On linux, install git-core using your favorite package management tool should do it.
On Mac OS, using Mac Port:
sudo port install git-core
clone the repositoty
git clone git://gitorious.org/git-rails/mainline.git
Make sure all the specs pass:
I’m not sure why rake does not see the task and I’ll fix this shortly
Then have at it!
And to do a local install and try it out:
Then once you have something you think would benefit others, create a clone and share it!