Jeremy: Did you update your buildbot? It looks like the deadlock occurred again:
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http://buildbot.python.org/all/builders/AMD64%20Windows7%20SP1%203.x/builds/7478/steps/test/logs/stdio

(...)
0:14:50 [398/400] test_concurrent_futures (101 sec) -- running: test_strptime (40 sec)
0:14:52 [399/400] test_ssl -- running: test_strptime (42 sec)

command timed out: 1200 seconds without output, attempting to kill
program finished with exit code 1
elapsedTime=2096.738000
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By the way, I don't understand why the faulthandler watch dog thread is unable to kill the main process and dump a traceback. I recently added a "faulthandler.dump_traceback_later" call Lib/test/libregrtest/runtest_mp.py. It uses a timeout of 15 min, it looks like buildbot kills the process after a timeout of 20 minutes "without output".