Another similar bug different exception in test_thread on AMD64 FreeBSD CURRENT Debug 3.6:

http://buildbot.python.org/all/builders/AMD64%20FreeBSD%20CURRENT%20Debug%203.6/builds/145/steps/test/logs/stdio


test_save_exception_state_on_error (test.test_thread.ThreadRunningTests) ... FAIL
test_stack_size (test.test_thread.ThreadRunningTests) ... ok
...

======================================================================
FAIL: test_save_exception_state_on_error (test.test_thread.ThreadRunningTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.6.koobs-freebsd-current/build/Lib/test/test_thread.py", line 148, in test_save_exception_state_on_error
    self.assertIn("Traceback", stderr.getvalue())
AssertionError: 'Traceback' not found in ''

----------------------------------------------------------------------
Ran 23 tests in 1.565s

FAILED (failures=1)
test test_thread failed