`git.go:150: cannot use nil as type string in return argument`
One would have to change the return-type for that (e.g. to *string), but this seems a little bit fugly. I think an empty string is warranted, because we return an error at the same time. If you rely on the returned path when err != nil it's your own fault imho ;)

If you have a cleaner suggestion, I'm open to it.