missing attribute causing a traceback when running trial

[jacques]

trial nevow.test
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/site-packages/twisted/python/usage.py", line 199, in parseOptions
    self.postOptions()
  File "/usr/local/lib/python2.5/site-packages/twisted/scripts/trial.py", line 279, in postOptions
    self['reporter'] = self._loadReporterByName(self['reporter'])
  File "/usr/local/lib/python2.5/site-packages/twisted/scripts/trial.py", line 265, in _loadReporterByName
    for p in plugin.getPlugins(itrial.IReporter):
  File "/usr/local/lib/python2.5/site-packages/twisted/plugin.py", line 227, in getPlugins
    allDropins = getCache(package)
--- <exception caught here> ---
  File "/usr/local/lib/python2.5/site-packages/twisted/plugin.py", line 178, in getCache
    provider = namedAny(module.__name__ + '.' + moduleName)
  File "/usr/local/lib/python2.5/site-packages/twisted/python/reflect.py", line 357, in namedAny
    topLevelPackage = __import__(trialname)
  File "/usr/local/lib/python2.5/site-packages/twisted/plugins/twisted_web2.py", line 7, in <module>
    from twisted.web2.iweb import IResource
  File "/usr/local/lib/python2.5/site-packages/twisted/web2/iweb.py", line 58, in <module>
    class IOldNevowResource(components.Interface):
exceptions.AttributeError: 'module' object has no attribute 'Interface'

[exarkun]

Reformatting description

[exarkun]

It looks like you have Twisted 2.5 installed, as well as something like Twisted Web2 0.1 or Twisted Web2 0.2. Unfortunately, these aren't compatible and can't be used together. There's not really anything to fix here, except to either uninstall web2 or install a more recent version which works with Twisted 2.5 (there is no released version which works with Twisted 2.5 at this time, but trunk@HEAD does).