(In reply to Nathan Froyd [:froydnj] from comment #5)
(In reply to Michael Woerister from comment #4)
We're tentatively on track move remaining PGO builds to 3-tier PGO soon. That would probably render this issue obsolete.
Can you tell me more about this? It's unclear to me how this interacts with planned PGO support in the Rust compiler.
The idea behind 3-tier/stage PGO (bug 1507330) is that we want to perform
the instrumented build, the actual profiling, and the profile-use build as
three separate tasks in automation. So--assuming I understand Chris
correctly--this issue wouldn't matter for automation because the profile-use
build would actually start in a clean directory. It still does matter for
local development and testing of anything PGO, because we don't have a good
story for implementing the 3-stage system there.
Yes, that's what I mean. We'll probably want to remove the current targets for doing a PGO build once the remaining builds are converted and implement a small script to run the stages locally for people testing things out.