Attempting to cluster rabbitmq-server with 'add-unit' doesn't work

rabbitmq-server has peer relations to setup mirrored queues, however, these hooks do not correctly setup the cluster. In the charm log on the new unit, I see:

2012-12-06 22:31:27,590: hook.executor@DEBUG: Running hook: /var/lib/juju/units/rabbitmq-server-1/charm/hooks/cluster-relation-changed
2012-12-06 22:31:27,636: statemachine@DEBUG: unitworkflowstate: transition complete configure (state started) {}
2012-12-06 22:31:27,647: juju.agents.unit@INFO: No upgrade flag set.
2012-12-06 22:31:27,973: unit.hook.api@INFO: rabbitmq-server: Firing hook cluster-relation-changed.
2012-12-06 22:31:28,782: hook.output@INFO: Stopping rabbitmq-server:
2012-12-06 22:31:29,065: hook.output@INFO: rabbitmq-server.

2012-12-06 22:31:29,089: hook.output@INFO: Starting rabbitmq-server:
2012-12-06 22:31:31,958: hook.output@INFO: SUCCESS

2012-12-06 22:31:31,964: hook.output@INFO: rabbitmq-server.

2012-12-06 22:31:32,201: hook.output@INFO: Resetting node 'rabbit@server-dc086009-fae5-40e6-8c10-315c15f6ae76' ...

2012-12-06 22:31:32,217: hook.output@ERROR: Error: mnesia_unexpectedly_running

2012-12-06 22:31:32,469: hook.output@INFO: Clustering node 'rabbit@server-dc086009-fae5-40e6-8c10-315c15f6ae76' with ['<email address hidden>',
                                                                           '<email address hidden>'] ...

2012-12-06 22:31:32,486: hook.output@ERROR: Error: mnesia_unexpectedly_running

2012-12-06 22:31:32,723: hook.output@INFO: Starting node 'rabbit@server-dc086009-fae5-40e6-8c10-315c15f6ae76' ...

2012-12-06 22:31:32,842: hook.output@INFO: ...done.

2012-12-06 22:31:33,158: unit.hook.api@INFO: rabbitmq-server: Hook cluster-relation-changed complete. Exiting 0
2012-12-06 22:31:33,199: hook.output@DEBUG: hook cluster-relation-changed exited, exit code 0.
2012-12-06 22:31:33,225: hook.executor@DEBUG: Hook complete: /var/lib/juju/units/rabbitmq-server-1/charm/hooks/cluster-relation-changed

'rabbitmqctl cluster_status' shows no running cluster. The charm needs to be updated to do this properly, and hooks should fail if such errors are encountered.