The GUI-updater handoff race: the Desktop fires SIGTERM + app.quit() and
spawns hermes-setup, but its Python backend (`python.exe -m
hermes_cli.main serve`) can survive the teardown. The Desktop is gone --
nothing will respawn that backend -- yet the venv-holder guard refused on
it and the update dead-ended with "Hermes is still running" while the
user had zero windows open (observed twice on 2026-08-09, 01:59 and
02:17, bootstrap-installer.log).
New `_orphaned_desktop_backend_pids()` classifies remaining holders: a
serve/dashboard backend whose supervising parent is provably dead (PID
gone, or recycled -- parent created after the child) is a straggler safe
to reap. Any live-parent backend, non-backend holder, or unprovable case
keeps the refusal exactly as before. Reaping uses the new
`_stop_process_trees()` (taskkill /T /F), mirroring the Desktop's
forceKillProcessTree and install.ps1's venv sweep so the managed
.hermes-runtime interpreter child dies with its launcher (#70026).
Builds on #81327 (salvaged intact underneath): that fixed the same
parent-only-kill gap in install.ps1's venv sweep; this closes the
remaining dead-end in the `hermes update` guard itself.
E2E on a real Windows box: spawned a detached orphan with a
backend-shaped argv -> classifier returned its PID and the tree reap
killed it; a non-backend orphan and the live Desktop backend (parent
alive) both returned None (refusal preserved).
Teknium
826bf9b6d8