TracMercurial 'module' object has no attribute 'directives'

[phill]

I've installed the FreeBSD trac 0.12.3 and mercurial 2.3 ports and the TracMercurial 0.12.0.29 plugin from source, I've checked in Admin->Plugins and the TracMercurial plugin is loaded but I get the following error:

Warning: Can't synchronise with repository "(default)" (Unsupported version control system "hg": No module named repo). Look in the Trac log for more information. 

Traceback (most recent call last):

  File "build/bdist.freebsd-9.0-RC1-amd64/egg/trac/loader.py", line 68, in _load_eggs

    entry.load(require=True)

  File "/usr/local/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg/pkg_resources.py", line 1954, in load

    entry = __import__(self.module_name, globals(),globals(), ['__name__'])

  File "/usr/local/lib/python2.7/site-packages/mercurial/demandimport.py", line 114, in _demandimport

    mod = _origimport(name, globals, locals)

  File "build/bdist.freebsd-9.0-RC1-amd64/egg/trac/mimeview/rst.py", line 155, in <module>

  File "/usr/local/lib/python2.7/site-packages/mercurial/demandimport.py", line 87, in __getattribute__

    return getattr(self._module, attr)

AttributeError: 'module' object has no attribute 'directives'

Any ideas what's going wrong?