missing 'plugins' directory breaks trial

[mlum@…]

I'm running 'trial buildbot' buildbot within the buildbot source. Running 'trial' is breaking in the following:

Traceback (most recent call last):
  File "/usr/local/bin/trial", line 24, in <module>
    run()
  File "/usr/local/lib/python2.5/site-packages/twisted/scripts/trial.py", line 341, in run
    suite = _getSuite(config)
  File "/usr/local/lib/python2.5/site-packages/twisted/scripts/trial.py", line 301, in _getSuite
    return loader.loadByNames(config['tests'], recurse)
  File "/usr/local/lib/python2.5/site-packages/twisted/trial/runner.py", line 635, in loadByNames
    for thing in sets.Set(things)]
  File "/usr/local/lib/python2.5/site-packages/twisted/trial/runner.py", line 592, in loadAnything
    return self.loadPackage(thing, recurse)
  File "/usr/local/lib/python2.5/site-packages/twisted/trial/runner.py", line 543, in loadPackage
    pkgobj = modules.getModule(package.__name__)
  File "/usr/local/lib/python2.5/site-packages/twisted/python/modules.py", line 762, in getModule
    return theSystemPath[moduleName]
  File "/usr/local/lib/python2.5/site-packages/twisted/python/modules.py", line 698, in __getitem__
    self._findEntryPathString(moduleObject)),
  File "/usr/local/lib/python2.5/site-packages/twisted/python/modules.py", line 651, in _findEntryPathString
    rval, modobj, pformat(self.importerCache))
AssertionError: '' for <module '__init__' from 'buildbot/__init__.pyc'> not in import cache {'/usr/local/bin': None,
 '/usr/local/bin/twisted/plugins': <imp.NullImporter object at 0x2aaaaab18100>,

[exarkun]

Reformatting description

[jml]

Best to treat it as a trial bug at first.

mlum, which version of buildbot were you using?

[glyph]

It's really a bug in t.p.m, so I'm very interested as well.

[exarkun]

This may be related to #2005.

[exarkun]

Probably #2489 too.

[jesstess]

The buildbot tests from the latest release run without issue with Twisted 11.0. Can someone speak up if this issue still exists for them?

[jesstess]

I'm going to go ahead and close this since we can't reproduce on the latest version of Twisted, but mlum if you find that this is still an issue please don't hesitate to re-open the ticket.