RFC: Automate opening a PR with merge 0.23 -> main

[danicheg]

It's an RFC, not an issue. Also, it's not a 'discussion' in terms of Github units, as I do not personally like them much. But if one feels triggered by that decision, feel free to move it to where you feel comfortable.

Subject

Simply put, manually opening a PR to merge 0.23 -> main once in a long period is painful:

• Someone doing that might not have the full context when encountering merge conflicts. What's worse, certain defects may silently seep into the codebase due to diverging semantics between the 0.23 and main branches.
• People who worked on patches in 0.23 may also lose context after a month or more has passed. Additionally, since we are FOSS, we may not attract (intentionally or not) the original authors to review the changes 0.23 -> main branch related to their contributions.
• This is a manual work from start to end.

Proposal

Introduce some automation around opening a PR with a merge 0.23 -> main. It's all about the Github Actions workflow that might be triggered by

• any merged PR to 0.23;
• cronjob once in a day/week/month (a week seems the most reasonable).

Those options have its drawbacks:

• The first one appears to be somewhat spammy, yet it maintains maximum context for the PR review. But do we have a lot of PRs to worry about in recent days?
• The second one appears to be a reasonable compromise. However, a week might sometimes be enough time to start losing context (what-a-week-huh.jpg), but it is still better than nothing.

Yes, but

• It won't reduce the required work on resolving conflicts.
• It's barely that PR with a merge 0.23 -> main could be automatically merged.
• It can be overwhelming. What should be done when it comes to opening a new PR while there is a previous one that hasn't been merged?

Thoughts?

Your possible input on the topic is highly appreciated.

[rossabaker]

I think it's a nice idea. But these merges are only tenable today, painful as they sometimes are, because main isn't that different from series/0.23. They are only going to get more painful, and at some point we'll have to say no more. But this automation seems relatively cheap, and on one of them we'll agree enough is enough and can turn it off.