This is the situation on both Linux and Darwin (r29636) today.
$ prove -v t/stm/runtime.t t/stm/runtime.... 1..5 ok 1 - choice (one thread) ok 2 # SKIP Intermittently failing everywhere ok 3 # SKIP Intermittently failing everywhere ok 4 - queue adapted for the library ok 5 - queue (non-blocking; nested) ok All tests successful. Files=1, Tests=5, 3 wallclock secs ( 0.01 usr 0.00 sys + 0.72 cusr 0.27 csys = 1.00 CPU) Result: PASS
