internal server error when deleting a branch

When trying to delete a branch, I'm getting an internal server error.

Some side info:

* running on Debian Squeeze
* using the PPA for maverick on http://ppa.launchpad.net/sloecode/ppa/ubuntu

URL: http://putake.aut.ac.nz/sc/p/the_garden/delete_branch?branch_name=trunk
File '/usr/lib/pymodules/python2.6/weberror/errormiddleware.py', line 162 in __call__
  app_iter = self.application(environ, sr_checker)
File '/usr/lib/pymodules/python2.6/repoze/who/middleware.py', line 107 in __call__
  app_iter = app(environ, wrapper.wrap_start_response)
File '/usr/lib/pymodules/python2.6/beaker/middleware.py', line 152 in __call__
  return self.wrap_app(environ, session_start_response)
File '/usr/lib/pymodules/python2.6/routes/middleware.py', line 131 in __call__
  response = self.app(environ, start_response)
File '/usr/lib/pymodules/python2.6/pylons/wsgiapp.py', line 124 in __call__
  response = self.dispatch(controller, environ, start_response)
File '/usr/lib/pymodules/python2.6/pylons/wsgiapp.py', line 327 in dispatch
  return controller(environ, start_response)
File '/usr/lib/python2.6/dist-packages/sloecode/lib/base.py', line 22 in __call__
  return WSGIController.__call__(self, environ, start_response)
File '/usr/lib/pymodules/python2.6/pylons/controllers/core.py', line 225 in __call__
  response = self._dispatch_call()
File '/usr/lib/pymodules/python2.6/pylons/controllers/core.py', line 176 in _dispatch_call
  response = self._inspect_call(func)
File '/usr/lib/pymodules/python2.6/pylons/controllers/core.py', line 108 in _inspect_call
  result = self._perform_call(func, args)
File '/usr/lib/pymodules/python2.6/pylons/controllers/core.py', line 60 in _perform_call
  return func(**args)
File '<string>', line 2 in delete_branch
File '/usr/lib/pymodules/python2.6/repoze/what/plugins/pylonshq/protectors.py', line 118 in wrap_action
  return action_(*args, **kwargs)
File '/usr/lib/python2.6/dist-packages/sloecode/controllers/project.py', line 73 in delete_branch
  repo.delete_branch(branch_name)
File '/usr/lib/python2.6/dist-packages/sloecode/bzr/display.py', line 52 in delete_branch
  (rscheme, _, _, _, _, rpath) = parse_url(self.repo.user_url)
AttributeError: 'CHKInventoryRepository' object has no attribute 'user_url'

CGI Variables
-------------
  AUTH_TYPE: 'cookie'
  DOCUMENT_ROOT: '/var/www'
  GATEWAY_INTERFACE: 'CGI/1.1'
  HTTP_ACCEPT: 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
  HTTP_ACCEPT_LANGUAGE: 'en-gb,en;q=0.7,en-us;q=0.3'
  HTTP_CONNECTION: 'Keep-Alive'
  HTTP_COOKIE: 'sloecode=f660d16cc9dabc3c87897a91135616d34c717b02a6238cefd583d0338e54ddf027536a4b; auth_tkt="cc3667130463155bcd86d4bf2b717f3f4f70fe66gkloss!"; auth_tkt="cc3667130463155bcd86d4bf2b717f3f4f70fe66gkloss!"; __utma=95478083.824699417.1280966703.1288654595.1288658055.10; MOIN_SESSION_80_ROOT_wiki=cc17926440f73b52d08d3d049161fe6ebb271f90; FixedLeftThemeViewSequence=%23sidebarSearch%2C%20%23sidebarPageLink%2C%20%23sidebarNavigation%2C%20%23sidebarPageActions%2C%20%23sidebarMoreActions%2C%20%23sidebarUser%2C%20%23sidebarTrail%2C%20%23sidebarTOC%2C%20%23%23%23sidebarMoreActions%2C%20; MOIN_SESSION_8000_ROOT_wiki=3ef05eddf20d2bcc7f1e746d3e4a14ed0cead2be'
  HTTP_DNT: '1'
  HTTP_HOST: 'putake.aut.ac.nz'
  HTTP_REFERER: 'https://putake.aut.ac.nz/sc/p/the_garden/index'
  HTTP_USER_AGENT: 'Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:11.0) Gecko/20100101 Firefox/11.0'
  HTTP_X_FORWARDED_FOR: '60.234.168.206'
  HTTP_X_FORWARDED_HOST: 'putake.aut.ac.nz'
  HTTP_X_FORWARDED_SERVER: 'putake.aut.ac.nz'
  PATH_INFO: '/p/the_garden/delete_branch'
  PATH_TRANSLATED: '/var/www/p/the_garden/delete_branch'
  QUERY_STRING: 'branch_name=trunk'
  REMOTE_ADDR: '60.234.168.206'
  REMOTE_PORT: '40287'
  REMOTE_USER: 'gkloss'
  REMOTE_USER_TOKENS: ['']
  REQUEST_METHOD: 'GET'
  REQUEST_URI: '/sc/p/the_garden/delete_branch?branch_name=trunk'
  SCRIPT_FILENAME: '/usr/share/sloecode/wsgi/sloecode.wsgi'
  SCRIPT_NAME: '/sc'
  SERVER_ADDR: '127.0.0.1'
  SERVER_ADMIN: '<email address hidden>'
  SERVER_NAME: 'putake.aut.ac.nz'
  SERVER_PORT: '8001'
  SERVER_PROTOCOL: 'HTTP/1.1'
  SERVER_SIGNATURE: '<address>Apache/2.2.16 (Debian) Server at putake.aut.ac.nz Port 8001</address>\n'
  SERVER_SOFTWARE: 'Apache/2.2.16 (Debian)'

WSGI Variables
--------------
  application: <repoze.who.middleware.PluggableAuthenticationMiddleware object at 0xba483c8c>
  beaker.get_session: <bound method SessionMiddleware._get_session of <beaker.middleware.SessionMiddleware object at 0xba17ac0c>>
  beaker.session: {'_accessed_time': 1332808264.8644519, '_creation_time': 1332805213.408365}
  mod_wsgi.application_group: 'putake.aut.ac.nz:8001|/sc'
  mod_wsgi.callable_object: 'application'
  mod_wsgi.handler_script: ''
  mod_wsgi.input_chunked: '0'
  mod_wsgi.listener_host: '127.0.0.1'
  mod_wsgi.listener_port: '8001'
  mod_wsgi.process_group: 'SloecodeWsgiDaemon'
  mod_wsgi.request_handler: 'wsgi-script'
  mod_wsgi.script_reloading: '1'
  mod_wsgi.version: (3, 3)
  paste.cookies: (<SimpleCookie: FixedLeftThemeViewSequence='%23sidebarSearch%2C%20%23sidebarPageLink%2C%20%23sidebarNavigation%2C%20%23sidebarPageActions%2C%20%23sidebarMoreActions%2C%20%23sidebarUser%2C%20%23sidebarTrail%2C%20%23sidebarTOC%2C%20%23%23%23sidebarMoreActions%2C%20' MOIN_SESSION_8000_ROOT_wiki='3ef05eddf20d2bcc7f1e746d3e4a14ed0cead2be' MOIN_SESSION_80_ROOT_wiki='cc17926440f73b52d08d3d049161fe6ebb271f90' __utma='95478083.824699417.1280966703.1288654595.1288658055.10' auth_tkt='cc3667130463155bcd86d4bf2b717f3f4f70fe66gkloss!' sloecode='f660d16cc9dabc3c87897a91135616d34c717b02a6238cefd583d0338e54ddf027536a4b'>, 'sloecode=f660d16cc9dabc3c87897a91135616d34c717b02a6238cefd583d0338e54ddf027536a4b; auth_tkt="cc3667130463155bcd86d4bf2b717f3f4f70fe66gkloss!"; auth_tkt="cc3667130463155bcd86d4bf2b717f3f4f70fe66gkloss!"; __utma=95478083.824699417.1280966703.1288654595.1288658055.10; MOIN_SESSION_80_ROOT_wiki=cc17926440f73b52d08d3d049161fe6ebb271f90; FixedLeftThemeViewSeque!
 nce=%23s...e4a14ed0cead2be')
  paste.parsed_dict_querystring: (MultiDict([('branch_name', 'trunk')]), 'branch_name=trunk')
  paste.parsed_querystring: ([('branch_name', 'trunk')], 'branch_name=trunk')
  paste.registry: <paste.registry.Registry object at 0xba8c5a4c>
  paste.throw_errors: True
  pylons.action_method: <bound method ProjectController.delete_branch of <sloecode.controllers.project.ProjectController object at 0xba93c7cc>>
  pylons.controller: <sloecode.controllers.project.ProjectController object at 0xba93c7cc>
  pylons.environ_config: {'session': 'beaker.session', 'cache': 'beaker.cache'}
  pylons.pylons: <pylons.util.PylonsContext object at 0xba93c7ac>
  pylons.routes_dict: {'action': u'delete_branch', 'controller': u'project', 'project_name': u'the_garden'}
  repoze.what.adapters: {'groups': None, 'permissions': None}
  repoze.what.credentials: {'repoze.what.userid': 'gkloss', 'groups': (), 'permissions': ()}
  repoze.who.identity: <repoze.who identity (hidden, dict-like) at 3130587580>
  repoze.who.logger: None
  repoze.who.plugins: {'sa_md': <repoze.who.plugins.sa.SQLAlchemyUserMDPlugin object at 0xba4838cc>, 'sa_auth': <repoze.who.plugins.sa.SQLAlchemyAuthenticatorPlugin object at 0xba1e730c>, 'auth_tkt': <AuthTktCookiePlugin 3125296300>, 'form': <FriendlyFormPlugin 3125297100>, 'authorization_md': <repoze.what.middleware.AuthorizationMetadata object at 0xba483dcc>}
  routes.route: <routes.route.Route object at 0xba17068c>
  routes.url: <routes.util.URLGenerator object at 0xba93cc8c>
  webob._parsed_query_vars: (GET([('branch_name', 'trunk')]), 'branch_name=trunk')
  webob.adhoc_attrs: {'language': 'en-us'}
  wsgi process: 'Multithreaded'
  wsgi.file_wrapper: <built-in method file_wrapper of mod_wsgi.Adapter object at 0xba8be2f0>
  wsgi.version: (1, 1)
  wsgiorg.routing_args: (<routes.util.URLGenerator object at 0xba93cc8c>, {'action': u'delete_branch', 'controller': u'project', 'project_name': u'the_garden'})