If you want to untrack an accidentally committed file, then retrack it later:
[pastacode lang=”bash” message=”” highlight=”” provider=”manual”]
git update-index --assume-unchanged path/to/file[/pastacode]
To untrack it and:
[pastacode lang=”bash” message=”” highlight=”” provider=”manual”]
git update-index --no-assume-unchanged path/to/file[/pastacode]
to retrack it later!
From here: http://stackoverflow.com/questions/6964297/untrack-files-from-git