[🐞 BUG] Crash on Stop Recording with Whisper Large model (macOS 26.5, M4, SIGABRT/assert_rtn)

[Ming-Sir-69]

Bug Description

FluidVoice crashes 100% of the time when stopping a recording with the Whisper Large model. The crash occurs immediately when clicking "Stop" — recording duration does not matter.

Environment

Item	Value
FluidVoice	v1.5.14 (11)
macOS	26.5 (25F71)
Hardware	Mac mini M4 (Mac16,10), 32GB RAM
Model	Whisper Large
Bug type	SIGABRT (assert_rtn)

Reproduction Steps

1. Download and activate Whisper Large model
2. Click "Start Recording" (any duration — 1s or 60s, same result)
3. Click "Stop"
4. App crashes immediately

Confirmed NOT Occurring With

All other models tested do NOT trigger this crash:

• Whisper Tiny, Base, Small, Medium ✅
• Apple ASR Legacy ✅
• Apple Speech macOS 26+ ✅
• Parakeet TDT V2/V3/Flash ✅

→ Only Whisper Large triggers the crash.

Crash Analysis (from .ips)

• Exception type: EXC_CRASH (SIGABRT)
• Faulting thread: Thread 7, queue com.apple.root.user-initiated-qos
• Key frames (all within FluidVoice binary):

  assert_rtn
  → FluidVoice + 4699724
  → FluidVoice + 4561172
  → FluidVoice + 4566888
  → FluidVoice + 4571896
  → FluidVoice + 4587684
  → FluidVoice + 4421940
  → FluidVoice + 1155044
  

• Root cause: The app hits an assertion failure in its internal state machine when stopping a recording that uses the Whisper Large model. This is likely a thread-safety issue or an unexpected model state transition specific to the large model's memory footprint/loading behavior.

Crash Reports

3 identical crash reports (.ips) were generated across 3 test runs (all within 4 minutes):

• FluidVoice-2026-06-04-190625.ips
• FluidVoice-2026-06-04-190702.ips
• FluidVoice-2026-06-04-190949.ips

Additional Notes

• Whisper Medium works perfectly as a workaround
• The issue appears to be a code-level assertion failure, not an OS-level resource kill (VM summary shows ~3.7GB malloc, well within the 32GB available)
• This may affect other users with M4 + macOS 26.5 + Whisper Large combination

[altic-dev]

would you be able to provide me with the audio that causes the issue? I don't use this at all - so no idea why it crashes. if yu give me a repro - happy to take a look.