Copilot's suppressed round-3 comment is right. The attempt-counted loop read
the output and then slept, so nothing ever observed the last interval: an
announcement arriving at 29.9s of a 30s budget was reported as a timeout, and
a spawn error or early exit landing in that window was misattributed the same
way. Inherited from the original smoke, but wrong either way.
Replace it with a deadline loop that re-reads state after every wait, the last
one included, and clamp the final wait to the deadline so the budget is a real
bound rather than one poll longer.
The regression test sets pollMs === timeoutMs, which makes the distinction
deterministic rather than a race: the attempt-counted loop gets exactly one
check, at t≈0 before the child has finished starting, then throws; the deadline
loop re-reads after the wait and sees the announcement. The child announces
immediately, ~2s inside the window, so a loaded runner can't flip it. Verified
both directions — the test fails against the old loop and passes against the
new one — and `npm run test:scripts` was repeated to confirm it is stable under
the full 116-test parallel run (an earlier margin-based version of this test
was not).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hzwzS8UvBsr4yZm7o7sev
Signed-off-by: cliffhall <cliff@futurescale.com>
6b4bf68b8b