Some tests can fail without detection

The failure is a combination of two bugs in Twisted.

The first is that Twisted's result adapter object passes a thing that looks like the result of sys.exc_info(), but isn't quite the same. Zope recently has come to rely on more features of the third value of that tuple; features that Trial doesn't provide.

At some point, Zope raises:
    AttributeError: "'_Frame' object has no attribute 'f_locals'"

Here's the pdb stack:

/home/jml/src/launchpad/ec2test-karmic-bug-424197/bin/test(219)?()
-> result = testrunner.run(defaults)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/__init__.py(32)run()
-> failed = run_internal(defaults, args, script_parts=script_parts)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/__init__.py(45)run_internal()
-> runner.run()
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/runner.py(136)run()
-> self.run_tests()
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/runner.py(216)run_tests()
-> setup_layers, self.failures, self.errors)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/runner.py(374)run_layer()
-> return run_tests(options, tests, layer_name, failures, errors)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/runner.py(306)run_tests()
-> test(result)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(632)__call__()
-> return self.run(*args, **kwargs)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(956)run()
-> d = self.deferSetUp(None, result)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(659)deferSetUp()
-> errbackArgs=(result,))
  /home/jml/src/launchpad/package-permission-love/lib/twisted/internet/defer.py(186)addCallbacks()
-> self._runCallbacks()
  /home/jml/src/launchpad/package-permission-love/lib/twisted/internet/defer.py(328)_runCallbacks()
-> self.result = callback(self.result, *args, **kw)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(675)deferTestMethod()
-> errbackArgs=(result,))
  /home/jml/src/launchpad/package-permission-love/lib/twisted/internet/defer.py(186)addCallbacks()
-> self._runCallbacks()
  /home/jml/src/launchpad/package-permission-love/lib/twisted/internet/defer.py(328)_runCallbacks()
-> self.result = callback(self.result, *args, **kw)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(694)_ebDeferTestMethod()
-> result.addFailure(self, f)
  /home/jml/src/launchpad/ec2test-karmic-bug-424197/lib/twisted/trial/unittest.py(1162)addFailure()
-> self.original.addFailure(test, self._exc_info(fail))
> /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/runner.py(714)addFailure()
-> exc_info)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/testing/testrunner/formatter.py(319)test_failure()
-> self.print_traceback("Failure in test %s" % test, exc_info)
  /home/jml/repos/lp-sourcedeps/eggs/zope.testing-3.8.1-py2.4.egg/zope/t...

I'm tempted to mark this Critical, it has to be said...

Fixed in devel r9461 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/devel/revision/9461>