Comment 2 for bug 1443541

To confirm that this issue is not specific to deploying OpenStack, I deployed this mysql bundle with Vivid and juju 1.23b4, which also resulted in juju panics.

http://bazaar.launchpad.net/~ost-maintainers/openstack-charm-testing/trunk/view/head:/bundles/dev/mysql-scale.yaml

juju stat: http://paste.ubuntu.com/10817168/
mysql/1 machine log: http://paste.ubuntu.com/10817269/

Commands used to deploy:
juju-deployer -v -c mysql-scale.yaml -d trusty
  ..or..
juju-deployer -v -c mysql-scale.yaml -d kilo

As an added note, the same mysql bundle deploys cleanly with juju 1.23b4 on Trusty (http://paste.ubuntu.com/10817202/).

Additional version info:
00:01:38.953 Juju-core ver: Installed: 1.23-beta4-0ubuntu1~14.04.1~juju1
00:01:38.968 Juju-core ppa: 500 http://ppa.launchpad.net/juju/devel/ubuntu/ trusty/main amd64 Packages 500 http://ppa.launchpad.net/juju/stable/ubuntu/ trusty/main amd64 Packages
00:01:38.984 Amulet ver: Installed: 1.10.0-0ubuntu3~ubuntu14.04.1~ppa1
00:01:39.000 Juju-deployer ver: Installed: 0.4.3-0ubuntu1~ubuntu14.04.1~ppa1