Code review comment for lp:~jameinel/juju-core/api-connect-upgrade-1199915

LGTM with verbose warnings; I would *really* appreciate a followup that
somehow tested this situation live, but I'm at a little bit of a loss
how to do that sanely.

https://codereview.appspot.com/10986044/diff/5002/cmd/jujud/upgradevalidation.go
File cmd/jujud/upgradevalidation.go (right):

https://codereview.appspot.com/10986044/diff/5002/cmd/jujud/upgradevalidation.go#newcode30
cmd/jujud/upgradevalidation.go:30: // Note: Should we try to do the
install anyway, just without the lock?
Yeah, I think so. Log a great big warning and see what you can do. If we
fail, we bomb out, and upstart gives us another try; eventually we'll
mess with the unit badly enough that we succeed, I suspect, and then we
have a working machine again... and at least the unit is somewhat
user-fixable.

https://codereview.appspot.com/10986044/