Get the slush stratum proxy working on a mac
So, while Mac includes python it does not include gcc by default, even once you've installed Xcode 4.2 or later. For now, grab that, go to preferences, downloads and get the command line tools.

Once a version of Xcode higher than 4.6 is out you'll have to find a new way to install gcc on your mac, as gcc will no longer be included, but I guess that's a question for another stackexchange, and likely a macports or homebrew solution.