The residue an interrupted update leaves behind is invisible: the server
runs, every doctor row reads OK, and the unit quietly still names a cache
directory Claude Code deleted during the update. Nothing surfaces it until
a reboot, when the dashboard does not come back and nothing recorded why.
- fastPathOk now rejects a stale unit, so the next SessionStart repairs it
instead of short-circuiting. `unitIsStale` is pure fs on purpose: that
path runs on every session and may not spawn a process.
- Repairing the unit is not restarting the server. A current, healthy
server keeps running and the corrected unit takes effect at the next
start (`pendingSystemdRestart = systemdOwned && needsServer`), and the
detached-spawn fallback is guarded by needsServer so a stale unit alone
cannot start a second server onto a bound port.
- systemdOwned now also requires the unit to be ACTIVE. Installed-but-
stopped owns nothing: skipping the stop there and asking systemd to start
would bind an occupied port and crash-loop under Restart=always.
- /agenthub-doctor gains a systemd row naming the consequence ("will NOT
come back after a reboot") and the fix. WARN, never FAIL — the dashboard
in front of you works, and having no unit at all is a normal setup.
The fast-path test pins the regression against an otherwise fully healthy
install, live server included; without a live server it would have passed
against the unfixed code either way.
A plugin self-update took the dashboard down and left it down. The chain
ran correctly up to the point where the bootstrap SIGTERMs the server it is
replacing — and that server was systemd-managed, with the bootstrap running
as its descendant, i.e. inside its cgroup. Two failures fired at once:
* the server exits 0, and `Restart=on-failure` reads a clean exit as
"meant to stop", so systemd did not bring it back;
* `KillMode=control-group` reaped the bootstrap itself, mid-run, before it
could repoint the unit at the new plugin root or write state.json.
Evidence from the incident: bootstrap.log ends at "stopped the server
started from the previous plugin version" with no systemd line after it,
.bootstrap.lock survived with a dead pid, state.json still named the
previous version, and the unit's ExecStart still pointed at the old cache
dir. The same truncation is visible on three earlier updates — those only
recovered because a later SessionStart bootstrapped again.
systemd-service.js now splits install into writeUserService (repoints the
unit, starts nothing) and restartUserService (--no-block). The bootstrap
skips the manual stop whenever a unit of ours owns the server, and defers
the restart past writeState and releaseLock, so being killed by its own
request costs nothing. The unit is Restart=always: a graceful SIGTERM from
anything must no longer read as "leave it stopped".
installUserService keeps its old semantics for `agenthub service install`,
which runs from a user's shell and is not in the cgroup.
nntrivi2001