Tests that exercise the dashboard's gateway-restart path can end up
spawning a REAL `python -m hermes_cli.main gateway restart` child when
the spawn seam is not intercepted. `_spawn_hermes_action` launches it
with start_new_session=True, so it outlives the pytest worker; the
child inherits the pytest-tmp HERMES_HOME, which is not a profile and
hashes to no service suffix, so `get_service_name()` resolves the
DEVELOPER's `hermes-gateway` unit, `systemd_restart` restarts the live
gateway, and without systemd the fallback runs `run_gateway()`
in-process forever and squats the webhook port.
Live repro on this machine (origin/main): an unintercepted spawn of
["gateway", "restart"] from a test restarted the production gateway
(MainPID 136820 -> 1689090, NRestarts=1). On 2026-09-03 a sibling
refactor moved `_spawn_hermes_action` from the `hermes_cli.web_server`
facade to `hermes_cli.web_server_gateway` ~10 minutes before the tests
were repointed; runs in that window patched a name production never
read and left 39 orphans alive for six days.
The live-system guard now rejects any subprocess primitive whose
command line the canonical matcher (`gateway.status.
_gateway_command_subcommand`) classifies as `gateway run|start|restart`.
Argv substrings are never consulted, so `gateway status`, `gateway
--help`, `hermes_cli.main serve`, etc. pass through. Three files that
deliberately spawn and reap a stub child with a gateway-shaped argv
(flock holders, sleep sleepers with an argv tail) opt out with the new
`spawns_gateway_lookalike` marker, which lifts only this check and keeps
os.kill guarded. Two canary tests pin the block and the pass-through.
hermes update decides restart ownership from the live grandchild argv,
not from an env marker. Newly generated plists now include the flag.
The stderr_timestamp wrapper upgrades only historical Hermes gateway
run shapes for stale plists and leaves arbitrary launchd children unmarked.
launchd only stamps XPC_SERVICE_NAME on its direct child. The timestamp
wrapper is that child, so the grandchild gateway sees XPC_SERVICE_NAME=0
and the supervised-conflict guard refuses the service's own spawn.
Forward HERMES_GATEWAY_EXTERNAL_SUPERVISOR=1 when the wrapper itself is
launchd-supervised. Interactive XPC_SERVICE_NAME=0 starts stay unmarked.
Fixes#86893
Teknium