Hey John,
Until about October my primary laptop was a Mac. I had been working with an old checkout of tcc. Back in June I made a commit that reverted a large collection of commits that most of the community deemed inappropriate, and at that time I believe that tcc didn't compile on Mac. I suggest checking out one of the commits from late 2013: I seem to recall that things were working fine then.
One of the tcc community (Miki?) works pretty hard on keeping tcc working on Mac, but he seems to be busy as of late. Also bear in mind that tcc cannot produce Mach-O executables, which is what Macs expect. This means that while tcc works as a JIT compiler on Mac, it does not build stand-alone executables.