The watchdog keyed on "a span has been open past the threshold". Spans nest, and `on_exit`
republishes the enclosing one deliberately — so between any two inner spans the slot shows a span
that has been open since the first frame, and the watchdog said so.
In a 105-second play session that was 13,658 of the log's 15,335 lines: `STALL: span
#2473901162497 has been running 209147 ms`, alternating with `STALL ended`, every ~75 ms, each one
re-reading /proc for 39 threads — inside the session it was there to measure. The instrument whose
whole job is to be trustworthy when nothing else is was the loudest liar in the log, and it could
not even name what it was accusing, because an enclosing span has no entry in `names`.
So `Slot::beat`, bumped on every enter and every exit. A stall is now a thread that has not entered
or exited anything for the threshold — which is what "wedged" means and what the module header
already claimed to be reporting. The end line also gets the real total rather than the duration at
first sighting, which is why both lines used to print the same number.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SgstFWtn1RxEJ5kVrpgYwn
gromandClaude Opus 5
21c0befdca