Comment 3 for bug 874681

it seems that trac-xmlrpc also outdated in oneiric. as a workaround these plugins could be installed using pip:

# pip install svn+http://svn.edgewall.com/repos/trac/plugins/0.12/mercurial-plugin
# pip install svn+http://trac-hacks.org/svn/xmlrpcplugin/trunk