Comment 3 for bug 1898966

Leadership lease expiry is managed separately in the controller, so there will always be a window where a hook may start and leadership could be lost part way through. The controller has no visibility to what the unit agent is doing (there are separate components in a distributed system) so any such coordination is impractical. Now that we store agent state in the controller though, maybe we can revisit that, but the complexity may not pay for itself.

Generally so far as I understand it, charms are written to catch leadership exceptions and exit the hook gracefully.

Generally, all units need to be informed when something happens, eg consume relation data change etc. So not having minions run hooks isn't really practical.