`Start-UiServer` printed the -SelfTestUi URL (and opened the browser window)
as soon as the TcpListener was bound, but the runspace that answers /progress
starts asynchronously — BeginInvoke returns before the pipeline is open and
the script block is JIT'd, which is seconds on a loaded runner. The kernel
accepted connections into the backlog during that gap and nobody answered
them. The self-test hit it three times (#90371 and two follow-ups each
widened a timeout instead of removing the race) and it just failed an
unrelated hermes_state.py PR (run 33591547099, two 5s stale-backlog
timeouts = red).
- windows.ps1: readiness handshake after BeginInvoke — one /progress
round-trip must succeed (≤15s) before the server is returned; on failure
tear the listener down and continue without UI. The URL now means
"serving", not "bound". Also fixes the browser opening to a page that never
loads on a slow machine.
- test: 1s per-attempt probe timeout so a single dead backlog socket cannot
consume half the readiness budget.
- CI: new `desktop_updater` classifier lane. tests/test_desktop_update_windows_*.py
spawn the real PowerShell script; the Windows-only job now runs them only
when scripts/desktop-update/**, the Electron updater launcher, conftest,
pyproject, or those tests change (push/dispatch fail open). A PR that
never touched that surface cannot be failed by its process timing.
A single urlopen(timeout=5) TimeoutError from the PS runspace listener
failed the test on a loaded runner (run 32440286339) even though the
listener recovered moments later — a transient stall is not the hang
this test guards. /progress sampling now retries until a deadline
(only a persistently unresponsive listener fails), the self-test hold
grows 10s -> 30s so retry time cannot push sampling past the held
stage, and the exit wait gets matching headroom.
test_progress_advances_while_the_orchestrator_blocks raced its subject on
both edges within one hour of PR CI (#90358):
- Run 1: sampled right after the shim URL printed, before the orchestrator
published its stage — caught the page boot default
('Hermes will open once done.' != 'Testing quiet update').
- Run 2 (rerun): with HOLD=4s on a slow runner, the second sample slid past
the hold and caught the cleared terminal state ('' != 'Testing quiet
update').
Fix: wait (<=10s) for the published stage to actually land before starting
the 1.5s stability window, and raise the hold to 10s so both samples land
inside it. Same assertions, same contract — just anchored to the event the
test is about instead of wall-clock luck.
The self-test grew a branch that spawns a Python child so pytest could prove
progress advances during one. It doesn't need to: /progress is answered from
its own runspace, so the existing hold already blocks the main thread, and
the spawn only exercised Invoke-HermesStep, which nothing here changes.
The Windows test now asserts the invariant instead of the self-test's stage
string, and the posix half -- previously untested, and the half that broke --
gets real coverage: serve-ui.py's wire shape, and posix.sh driven end to end
with a stub `hermes` that reports which stage was on screen while it ran.
Teknium