"A simpler way to do this is to add a post-receive script which runs the chmod command after every push to the 'hub' repo on the server. Add the following line to hooks/post-receive inside your git folder on the server:

chmod -Rf u+w /path/to/git/repo/objects"

I needed our hudson CI builds to auto-fire when a developer pushes their code changes to our canonical/upstream git repositories.

"turns out the post-receive hook starts out with the GIT_DIR environment variable set to the repo/.git folder, so no matter what path you 'cd' into it will always try to run any following git commands there. Fixing this is simply a matter of unsetting the GIT_DIR (thanks to Ulrich Petri for the elegant env -i solution)"

"Oh, this one took me a while to figure out. Lets say you want to setup a git repository on your server that whenever you push into it updates its working tree. Why? Well, because this can be a very convenient workflow for a small project where you want to be able to quickly push changes out without any fancy deploy mechanism."