Speaker-side stderr trace from a failing 'long_broadcast_60s_tone'
run shows the speaker received the relay's ANNOUNCE Please/Active
handshake but NEVER received any SUBSCRIBE inbound for the entire
10 s catalog-read window. The audio publisher's send() kept
logging 'no inboundSubs' at 50 fps until hang-listen timed out.
Diagnosis: moq-rs 0.10.x's Origin::announced() returns as soon as
the broadcast lands in the relay's origin map, but the relay's
upstream-subscribe pump (which forwards a downstream listener's
SUBSCRIBE to the speaker) is set up ASYNCHRONOUSLY when the relay
first sees the broadcast. Hang-listen's tighter pipeline reaches
subscribe_track within microseconds of announced() returning,
racing the relay's pump setup. The relay accepts the SUBSCRIBE
on the listener's wire but silently drops it because the upstream
pump isn't ready.
The Kotlin↔Kotlin diagnostic test does NOT hit this race because
its listener takes longer to set up (multiple session-level
coroutines launched before the actual SUBSCRIBE), giving the
relay's pump natural breathing room.
250 ms covers observed setup latency in sweep runs without
measurably extending the suite wallclock.
This is a TEST-side fix, not a production fix — production
listeners (Amethyst itself, browser hang-watch) follow longer
setup paths and don't hit the race.
Claude
2070573749