http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50862
--- Comment #15 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2011-10-26 13:55:25 UTC --- Shouldn't the testcase contain: // { dg-require-sched-yield "" } ? I'm getting a failure because this_thread::yield is not defined, and 30_threads/this_thread/2.cc contains this directive so as to not fail in the same way.