Comment 9 for bug 1907920

That has a lot of assumptions, the chiefest being that said numbering and naming is public.
This is the first I've heard of it and I've been using ubuntu since somewhere around 7, after switching off of debian. Most of the third party sources are still back further.
In my case, I'd missed the notice likely because it showed up in the middle of a work deadline and got in the way and was dismissed, likely, then never saw another notice anywhere, so was suprised when everything apt-related stopped working without explanation or warning (404 code is neither), and that none of the related tools said anything other than host unreachable or file unknown.

So my suggestion is to have a warning printed out by apt or dpkg when running in a terminal about EOL / past EOL. Would be sufficient.

And then additional repeated surprises as the upgrade tool meant to solve this kept aborting, crashing and failing - which is where this bug report came from.

I am posting in the hopes some of the notes help someone else not waste two days of their life trying to debug this kind of mess, as it did me. And in the distant hopes someone will prevent this kind of failed upgrade path from either being known about or failing repeatedly from happening again.