Comment 11 for bug 1197648

This is actually caused by a bug in python-eventlet < 0.13 and has now been fixed. See:

https://bitbucket.org/eventlet/eventlet/issue/149/yield-in-except-clause-with-wilcard-raise

It is also an issue the affects all services in Openstack so rather than patch every occurence of the issue, upgrade python-eventlet to this latest version and your problem will hopefully go away.