Feature: Mention maintainers of newly-broken packages?

[timbertson]

This update to pylint caused a package I maintain (gup) to break. I'm OK with that happening (it was legitimate and I don't think the pylint change should have to be blocked by that), but but it feels like a missed opportunity.

If I had been mentioned on the original PR, I would have known about the breakage straight away (and perhaps been able to fix it before the update was even merged), rather than having the package remain broken until a user noticed a few weeks later and raised an issue.

Proposal:

When an update breaks dependant packages, we can ping (either mention or request reviews from) the maintainers for those packages in the update PR.

It's possible this would cause a lot of noise, so ideally we might want some conditions:

• only ping maintainers when a reviewer decides that this PR should be merged (or at the very latest, only ping when the PR actually is merged?)
• restrict to a threshold of, say 50 maintainers to prevent chaos when a large breaking change is merged (ideally this wouldn't get merged if it breaks so much, but stuff happens 🤷 ).

I think most maintainers would welcome the information, but it might also be useful to let maintainers specify what kinds of notifications they want (e.g. maybe many don't want to be pinged about darwin failures, there's a lot more of those).

If this is a feature you'd be interested in, I'd be willing to have an attempt. I've never touched this codebase though, so pointers would be appreciated :)

[rhendric]

I asked about this a little while ago on Discourse, and there was enough support for getting GitHub pings that I think it'd be a good idea to try. We already run nixpkgs-review, which (when it doesn't timeout) should allow us to get a list of broken dependents; and then that list could be fed to a Nix expression that gets GH usernames.