P3 --- required status checks are name-coupled to job names, and a
required context that no longer exists does NOT fail. It leaves every
PR pinned on "Expected --- waiting for status" forever, which is `main`
becoming unmergeable by policy rather than by a red run. Three of this
lane's own deferrals will do exactly that: the macOS matrix trim
removes two contexts outright, and nextest or the serial/parallel split
rename or add jobs.
The rule is now in the ledger entry --- any job rename, removal, or
matrix change updates the branch-protection required-checks list in the
same motion --- and it is recorded HERE deliberately, because this is
the single entry that both enabled protection and named the lanes that
will invalidate it. Arming the warning anywhere else would separate the
trap from the thing that sets it.
P4 --- the rewritten top comment said "everything else keeps 25 against
a sub-4-minute observed max" and dropped the clause noting that
`m6-perf-gates` keeps its own tighter 15. Restored. Worth the fixup in
a change whose entire subject was comments matching reality.
Beyond the PR, and taken here rather than deferred: `TEST_IMPROVEMENT.md`
on `main` still said "no branch protection on `main` (verified via API:
404, so every job is advisory)" and listed §5.1 as open. Both went
stale during this session, and THIS lane is what made them stale, so it
carries the correction rather than leaving it for whoever touches the
file next. Struck through in both places rather than rewritten: the 404
was a true reading at audit time, and the document is the arc's scoping
record, so what changed is more useful than a clean-looking present
tense. Note also that protection shipped wider than §5.1 proposed ---
all 12 contexts required, not the cheap-jobs-only starter --- which the
correction states.
Verified: YAML parses; the seam check from update-protocol rule 6 finds
no double blanks; `git diff --check` clean.
Levi Neuwirth
2554bfcbb9