Prevent 'downgrades' from maintenance minors to older minor releases for the next major version

Reorganizing the IS a little and surfacing the urgent child issue.

xjm → credited Balu Ertl → .

xjm → credited drumm → .

Some ideas from @Balu Ertl in #d11readiness Slack:

• Write an article on drupal.org/blog. Include a well-drawn illustration to visually support the understanding through an example (eg. CKEditor might get newer in 10.4 than in 11.0).
• On the release notes page of 10.4, 11.0 and 11.1 compose a paragraph of text referencing the article above.
• Post a change record focusing mainly on the related code change (if any), referencing the above article only as a background.
• Core’s newly implemented Announcements module should also show up a post in relation with this topic – (if that feed is different from the Drupal blog)
• Make sure the above article is curated into the upcoming editions of the Weekly Drop newsletter
• Tweet the article link by the TheDropIsAlwaysMoving

@drumm also said in a meeting with some core committers and DA infra staff that we should do whatever we can to enforce this at the Composer level, and not add any special custom metadata to Drupal.org about it (i.e., ideally not branch or release configurations on d.o.)

If I understand correctly, everything is still backports and 11.1 will be released before 10.4. A forward upgrade will always be possible, but should skip the earlier minor versions.

Ideally the Composer solver should disregard 11.0 when someone has 10.4. Maybe conflict could be added to the site’s root composer.json?

Otherwise, a post-update warning is good. Many might be skipping 11.0 when 11.1 is available anyway. Someone who does land in this situation isn’t at a dead end.

A lot of the specific implementation issues for this will end up as 11.1/10.4. We might also want to backport things to 11.0 where necessary, but that meta will be marked fixed shortly, so tracking under the active one instead.

The child issues are done, so I think this is done too?

At #3463226-25: Use the new equivalent updates API to prevent updates from 10.4.0 to 11.0.0 → , @catch raised the possibility we might want another pair of equivalent updates to prevent downgrading from 10.5.x to 11.1.x. Should we open another follow-up for that under this meta?

@dww, yes, that makes sense to me. Thanks.

Yeah at some point we will have a 10.x minor with no updates or new APIs, and an update to 10.6.x to 11.2.x might be OK, but even if that happens we probably still need an issue each time so we don't forget to check.