Comment 7 for bug 1537095

The same happened again with 1.9.0. And I think an image update was happening in the background. At least, the logs show one started one minute before juju bootstrap failed saying that trusty is not a valid ubuntu release.

The error we got is this from juju:
01:11:39 2016-03-15 01:11:39 ERROR juju.cmd supercommand.go:429 failed to bootstrap environment: cannot start bootstrap instance: gomaasapi: got error back from server: 400 BAD REQUEST ({"distro_series": ["'trusty' is not a valid distro_series. It should be one of: '', 'ubuntu/xenial'."]})

I'm going to attach several logs, including the jenkins console where the above error appeared.