A pull request labelled macos-priority when its run starts waits in its
own line under the same rule, and the normal line counts every priority
run still waiting as holding two runners, so the next free runners go
to it. It still waits for runners in use and for main's reserve.
Co-authored-by: raistlin7447 <kris.austin@gmail.com>
A pull request's macOS build now waits in one repo-wide line, from a
Linux job, until the macOS runners every active Build all run holds or
still needs leave two free. A run is let in whole: its first arch takes
both runners and its second goes straight through, since letting arches
in one at a time deadlocks with every runner held by a run waiting for
its other arch. Push, nightly and manual runs reserve two runners until
their macOS work is done, and a pull request run keeps its two until its
universal build and tests finish, so jobs that never pass the line are
accounted for. Queued jobs count as busy. API errors and a four-hour
limit let the build in rather than block it.
Co-authored-by: raistlin7447 <kris.austin@gmail.com>
