http://buildbot.python.org/all/builders/AMD64%20FreeBSD%209.x%203.x/builds/4966/steps/test/logs/stdio is failing with a fatal Python error:

0:06:13 [224/405/1] test_threading crashed -- running: test_datetime (162 sec)
Fatal Python error: Py_EndInterpreter: not the last thread

Current thread 0x0000000801807400 (most recent call first):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/support/__init__.py", line 2450 in run_in_subinterp
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/test_threading.py", line 877 in test_threads_join_2
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/case.py", line 600 in run
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/case.py", line 648 in __call__
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 122 in run
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 84 in __call__
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 122 in run
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 84 in __call__
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 122 in run
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/suite.py", line 84 in __call__
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/unittest/runner.py", line 176 in run
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/support/__init__.py", line 1815 in _run_suite
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/support/__init__.py", line 1849 in run_unittest
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/runtest.py", line 163 in test_runner
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/runtest.py", line 164 in runtest_inner
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/runtest.py", line 119 in runtest
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/runtest_mp.py", line 71 in run_tests_slave
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 475 in _main
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 468 in main
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 532 in main
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/regrtest.py", line 46 in _main
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/regrtest.py", line 50 in <module>
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/runpy.py", line 85 in _run_code
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/runpy.py", line 193 in _run_module_as_main
Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/__main__.py", line 2, in <module>
    main()
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 532, in main
    Regrtest().main(tests=tests, **kwargs)
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 468, in main
    self._main(tests, kwargs)
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 490, in _main
    self.run_tests()
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/main.py", line 416, in run_tests
    run_tests_multiprocess(self)
  File "/usr/home/buildbot/python/3.x.koobs-freebsd9/build/Lib/test/libregrtest/runtest_mp.py", line 221, in run_tests_multiprocess
    raise Exception(msg)
Exception: Child error on test_threading: Exit code -6
*** [buildbottest] Error code 1