destroy-service on subordinate throws exception

[David Medberry]

python juju
juju 0.6.0.1+bzr616-0juju2~quantal1

When destroy-service is run on a subordinate, an exception is thrown in the debug log.

Steps to reproduce:

juju bootstrap
# open juju debug-log in a separate window
juju deploy ubuntu
juju deploy ganglia-node # currently using one from a bzr branch since charmstore version is broken

# every subordinate I've tried though has failed, this seems to be independent of the specific subordinate
# wait for the ubuntu service agent to be ready

juju add-relation ganglia-node ubuntu

#all is well at this point

juju destroy-service ubuntu #must destroy principal first

#all is still well in debug-log

juju destroy-service ganglia-node

Look for exception in debug-log stream. Trouble seems to start with...

2013-02-19 21:51:01,579 Machine:3: unit.deploy INFO: Stopped service unit ubuntu/0
2013-02-19 21:52:18,003 unit:ganglia-node/0: twisted ERROR: Unhandled error in Deferred:

(and that "Unhandled error in Deferred:" looks the same for other subordinate charms.)