Quick one today to remind others and perhaps my future self. After my upgrade to Mountain Lion, git was missing. Surprise!
Easy fix for me, obtained via https://answers.atlassian.com/questions/72981/error-after-upgrading-to-mountain-lion-os-git-svn … (Thanks!)
In Xcode, we just go to Preferences > Downloads and click install next to “Command Line
Hope this helps! It certainly easier to git push when you actually have git 😉