Four silences in one afternoon, with a gig that night, and every health check
reporting perfect: SC up with zero restarts, Tidal holding 6010, 48 graph links
present, master at -0.2 dB, interface clocking 48 kHz both ways. All true, all
useless.
What cracked it was PLN mentioning the system beeps had gone 'legato 0.2'. A
device that truncates a short sound is a device being restarted, and nothing in
the stack could see that because every lens sampled a moment and the fault lived
between them. trigger_time turned out to be the only restart counter anything
publishes: the UMC's playback stream had restarted 26 times in 15 minutes while
its capture stream — which drives the whole graph — never restarted once.
The log's real subject is the two tools I built to find it, and the fact that
both shipped blind. rig-pulse called SOUND on 'synths > 0 or peak > 1.5%' when
this rig idles at 71 synths and 17.7%, so it read healthy straight through a
silence its owner was complaining about. Then it learned the floor as a running
minimum, which fails because the floor rises. Meanwhile audio-lens compared
consecutive polls with a half-second minimum gap while polling every quarter
second, so its rate and stall checks never ran at all.
A check that never fires is indistinguishable from a check that passes, and the
only reason I found all three is that the rig kept obligingly breaking while I
watched.
