- https://twitter.com/MikolajBuchwald/status/1527780234254290946
- https://gist.github.com/FauxFaux/9686f285102bbaa59d63?permalink_comment_id=4174656#gistcomment-4174656
(do-release-upgrade's source code): https://git.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/tree/do-release-upgrade
References: