[Metacello] How to specify a github project

and git pull and open a local github MCDirectory, on the github-cache. I looked inside #ensureRecentMetacello and got lost. I would like to test the same with MagicMouse! Instead of this:

Metacello new
   baseline: 'MagicMouse';
   repository: 'filetree:///home/quotar/tribe/MagicMouse/packages';
   load

I want to specify

github://MagicMouse/magicmouse:master/repository

Is it possible somehow?

-- 
Kindly,
Robert