When I run git add -p, I see:
git add -p
Can\'t locate Git.pm in @INC (@INC contains: /usr/local/lib/perl5/site_perl /Library/Perl/5.12/darwin-thread-multi-2lev
I had the same issue.
Finally I had resolved it by installing git from source and having my installation in my PATH rather the one from XCode.
git