Its using that later for installing packages using its native package system

If I understand the code right, it only installs things automatically when it detects homebrew.

Besides, it _assumes you're on a Mac_ if none of these three programs are found.

From what I can guess, if you happen to be on a non-supported linux distribution (or any non-OSX OS with sh, really) and have clang installed, the script will go as far as running https://raw.github.com/mxcl/homebrew/go which should fail fast for lack of a /usr/bin/sw_vers binary.

I'm not brave enough to actually run the script and check, though.

Go fix it?