Comment 1 for bug 984640

This is an interesting one.

We can (and hopefully *will*) easily add the ability to preflight constraints before they ever leave the CLI; but we can't ever *guarantee* a successful launch by the provisioning agent (because, for example, someone could grab that machine in the interval between the preflight and the actual request).

Offhand, I suspect that `juju status` would be the right way to communicate this back -- so rather than just seeing "machine-state: pending" forever, you instead see "machine-state: launch-error" (With, perhaps, a launch-error field that only shows up if the machine's in that state?).

Independent of the preflighting, which is IMO a necessity anyway, would that be a reasonable way of communicating unpredictable problems?