canonical-livepatch kernel-upgrade-required hangs in dbus 1.12.20-2ubuntu4 upgrade on upgrade impish to jammy

[Marvin Barley]

When doing a ``do-relelase-upgrade -d'' from impish 21.10 to jammy 22.04, the system hang in
dbus upgrade, reporting that a restart of the system is required.

``ps -ef'' revealed that canonical-livepatch was hanging in ``canonical-livepatch kernel-upgrade-required'' command called from dbus 1.12.20-2ubuntu4 postinst script.

kill -HUP on livepatch process did not work, but after kill -TERM, the installation proceeded.

Hope this helps.

I failed to reproduce error as I cannot rollback the upgrade to jammy 22.04.

Best regards,
Marvin