http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51906
--- Comment #44 from Iain Sandoe <iains at gcc dot gnu.org> 2012-02-03 17:14:43 UTC --- if you are saying that: code targeted at 10.6 produced on 10.7 (using the correct 10.6 SDK) doesn't run properly on 10.7 - no surprise - that's just exposing the OS bug. If you are saying: code targeted at 10.6 produced on 10.7 (using the correct 10.6 SDK) doesn't run properly on 10.6, then that is something that people should be concerned about.