Tried this out (see lp:~mnordhoff/loggerhead/cheezum). Got this:

> 2010-05-04 02:38:18,853 DEBUG    paste.httpserver.ThreadPool: Added task (0 tasks queued)
> 2010-05-04 02:38:20,627 ERROR    loggerhead./bzr-svn/trivial/check_versions_nameerror:  exceptions.TypeError: list objects are unhashable
> Traceback (most recent call last):
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/error.py", line 31, in __call__
>     return self.application(environ, start_response)
>   File "/var/lib/python-support/python2.5/paste/httpexceptions.py", line 632, in __call__
>     return self.application(environ, start_response)
>   File "/var/lib/python-support/python2.5/paste/deploy/config.py", line 276, in __call__
>     return self.app(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/main.py", line 165, in new_app
>     return application(environ, start_response)
>   File "/usr/local/lib/python2.5/site-packages/Dozer-0.1-py2.5.egg/dozer/__init__.py", line 76, in __call__
>     return self.app(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/main.py", line 142, in new_app
>     return application(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/transport.py", line 169, in __call__
>     transport, self)(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/transport.py", line 126, in __call__
>     return self.app_for_non_branch(environ)(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/transport.py", line 126, in __call__
>     return self.app_for_non_branch(environ)(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/transport.py", line 126, in __call__
>     return self.app_for_non_branch(environ)(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/transport.py", line 132, in __call__
>     return self.app_for_branch(b)(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/branch.py", line 190, in app
>     val = do_stuff()
>   File "/home/mnordhoff/loggerhead/loggerhead/apps/branch.py", line 182, in do_stuff
>     return c(environ, start_response)
>   File "/home/mnordhoff/loggerhead/loggerhead/controllers/__init__.py", line 93, in __call__
>     vals.update(self.get_values(path, kwargs, headers))
>   File "/home/mnordhoff/loggerhead/loggerhead/controllers/revision_ui.py", line 45, in get_values
>     revid = self.get_revid()
>   File "/home/mnordhoff/loggerhead/loggerhead/controllers/__init__.py", line 115, in get_revid
>     return h.fix_revid(self.args[0])
>   File "/home/mnordhoff/loggerhead/loggerhead/history.py", line 453, in fix_revid
>     val = self.get_revid_for_revno([revid])[revid]
>   File "/home/mnordhoff/loggerhead/loggerhead/history.py", line 364, in get_revid_for_revno
>     revid = self._revno_revid_cache.get(revno_str)
>   File "/home/mnordhoff/loggerhead/loggerhead/history.py", line 241, in get
>     cached = self._cache.get((self._branch_tip, key))
>   File "/usr/local/co/bzr/bzr/bzr.dev/bzrlib/lru_cache.py", line 184, in get
>     node = self._cache.get(key, None)
> TypeError: list objects are unhashable
> 2010-05-04 02:38:20,636 INFO     loggerhead./bzr-svn/trivial/check_versions_nameerror: Getting information for ErrorUI: 0.000 secs
> 2010-05-04 02:38:20,636 INFO     wsgi: 127.0.0.1 - - [04/May/2010:02:38:18 +0000] "GET /loggerhead/bzr-svn/trivial/check_versions_nameerror/revision/950.1.107/repos.c HTTP/1.0" 200 - "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
> 2010-05-04 02:38:20,646 INFO     loggerhead./bzr-svn/trivial/check_versions_nameerror: Rendering ErrorUI: 0.006 secs, 3920 bytes