Spurious test failure in TestPostgresListenerService.test__handles_missing_system_handler_on_notification

[LaMont Jones]

in 251 iterations, 20 failures:
======================================================================
FAIL: maasserver.tests.test_listener.TestPostgresListenerService.test__handles_missing_system_handler_on_notification
----------------------------------------------------------------------
testtools.testresult.real._StringException: Twisted logs: {{{Listening for database notifications.Connection closed.}}}

Traceback (most recent call last):
  File "/srv/ssd/lamont/maas/bug-1640147/src/maastesting/runtest.py", line 134, in _run_user
    result = function(*args, **kwargs)
  File "/home/lamont/.buildout/eggs/testtools-2.2.0-py3.5.egg/testtools/testcase.py", line 719, in _run_test_method
    return self._get_test_method()()
  File "/usr/lib/python3/dist-packages/crochet/_eventloop.py", line 461, in wrapper
    return eventual_result.wait(timeout)
  File "/usr/lib/python3/dist-packages/crochet/_eventloop.py", line 231, in wait
    result.raiseException()
  File "/usr/lib/python3/dist-packages/twisted/python/failure.py", line 368, in raiseException
    raise self.value.with_traceback(self.tb)
  File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1128, in _inlineCallbacks
    result = g.send(result)
  File "/srv/ssd/lamont/maas/bug-1640147/src/maasserver/tests/test_listener.py", line 124, in test__handles_missing_system_handler_on_notification
    self.assertFalse("sys_test" in listener.listeners)
  File "/usr/lib/python3/dist-packages/unittest2/case.py", line 696, in assertFalse
    raise self.failureException(msg)
AssertionError: True is not false

[Andres Rodriguez (andreserl)]

We believe this is no longer an issue in the latest releases of MAAS. Please upgrade to the latest version of MAAS, and If you believe this issue is still present, please re-open this bug report or file a new one.