Meh, I'd blame it on Unity first. I keep hearing that Unity can be either a gift from God or a curse from Satan.
I haven't done any compiling for a while, but didn't there used to be a Linux compiler that could compile cross platform? That might solve your Mac problem.
Also, I think I saw an Open Source Mac OS X for installing on x86_64 machines just the other day. I don't pay much attention to Mac, but maybe you could install that on a USB drive or an SSD or something and do your Mac compiling that way? Maybe? No clue if Mac will compile across platforms, but...?