darinmorrison/homebrew-haskell — pull request #20 by jspahrsummers (2013-09-13 08:33:51+00:00)
Title: Use GCC no matter what version of OS X

Xcode 5 can be installed on 10.8, so the OS check isn't a reliable way to identify it, and I don't think there'd be any ill effects from doing this on Xcode 4 as well.