http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53578
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-06-06 10:43:22 UTC --- That's because ext/concurrence.h is included throughout the library. I plan to add __gthread_recursive_mutex_destroy on trunk but any fix on the release branches will have to be less intrusive.
