A new proposal has been announced: Move query implementation outside rustc_middle #388. It will be announced at the next meeting to try and draw attention to it, but usually MCPs are not discussed during triage meetings. If you think this would benefit from discussion amongst the team, consider proposing a design meeting.
I think it would be interesting to see how much this changes the compile times. Would it be worth it to run perf on #70951?
@cjgillot does this obsolete mcp compiler-team#277 ?
I could not find a satisfactory design for mcp 277. It should be closed, yes.