Pull in an other GIT repo into your own for modification.
For my led clock I wanted to be sure that I have the modified environment at all times.
After some googling I found this:
<pre>git remote add rack_remote firstname.lastname@example.org:schacon/rack.git git fetch rack_remote git merge -s ours --no-commit rack_remote/master git read-tree --prefix=rack/ -u rack_remote/master git commit -m "Imported rack as a subtree."</pre> Note that submodules will be gone. I've fixed this by moving the .gitmodules file into my main repo and changed the paths