run_job() constructs SessionDB() synchronously with no timeout of its
own, unlike the agent's run_conversation call further down, which is
already bounded by HERMES_CRON_TIMEOUT. A wedged sqlite3.connect (e.g.
a stale flock from a crashed sibling process) hangs this call
indefinitely.
That hang is invisible to every existing cron safeguard because it
happens before _submit_with_guard's future exists: the finally block
that discards the job ID from _running_job_ids never runs. The job
stays wedged "running" — every later tick logs "already running —
skipping" — until the whole gateway process is restarted.
Observed in production: a cron job's worker thread was confirmed via
a live py-spy thread dump to be parked inside SessionDB.__init__'s
sqlite3.connect for 3+ days, silently skipping every scheduled fire
in between across a gateway process that otherwise stayed healthy.
Bound the SessionDB() construction with its own timeout
(HERMES_CRON_SESSION_DB_TIMEOUT, default 10s), following the same
bounded-thread-pool pattern already used elsewhere in this file (the
delivery retry path, and the agent inactivity watchdog just below).
On timeout, log at ERROR and proceed with session_db=None instead of
degrading silently to debug level, since an actual hang here is a new
condition worth surfacing.
Adds tests/cron/test_sessiondb_init_hang.py, including an end-to-end
regression proving the dispatch guard is released and a subsequent
tick can fire the same job again after a simulated hang.
Minhao HU
c675e7c793