Temp WAV files in /dev/shm not cleaned up on error → shm fills → sox RIFF header failures

[meckmyday-source]

Summary

Temp WAV files in /dev/shm are not cleaned up on certain error paths, leading to shm filling completely. Once shm is full, sox writes 0-byte WAVs and subsequent combines fail with RIFF header errors, and TrunkRecorder stops producing call files until restarted.

Environment

• Docker image: robotastic/trunk-recorder:latest (Created: 2025-12-11)
• Host: Raspberry Pi
• /dev/shm size: 512M
• Issue observed intermittently before and after 2025-12-11 (container rebuild was an attempted mitigation)

Behavior

• Normal: /dev/shm holds ~20–30 min of temp WAVs and old ones get deleted.
• Failure: temp WAVs stop being deleted, shm fills to 100%.
• After fill: new WAVs are 0 bytes → sox RIFF errors → no output to /data.
• Restart container restores normal behavior.
• This does not happen continuously; it appears after certain error conditions and then never self-recovers.

Logs/snippet

(Include short snippet)
sox FAIL formats: can't open input file `/dev/shm/...wav': WAVE: RIFF header not found
Failed to combine recordings

Evidence

I added a watchdog that monitors /dev/shm usage; restarting the container immediately restores normal cleanup behavior.

Suggested area

Likely a cleanup code path not being hit after combine/convert errors. This is reproducible over time.