In short, a patch was applied to libcdio, but I don't have a means to test
it. I'd appreciate it if those of you who do have OSX could try building
from libcdio from git to see make sure things aren't broken.

An issue was reporited in https://savannah.gnu.org/bugs/?30019 where
libcdio doesn't build native drivers for
OSX 10.6 Snow Leopard. Someone anonymously posted a patch, however no
information has yet been given regarding which OSX releases this has been
tested on.

I've tried to make the patch backward compatible, but again I don't have
OSX to test on. So I'd appreciate it if others could try building on OSX
now.