Let arecord die with the assistant

It was the only child started without PR_SET_PDEATHSIG. The assistant
died with no log line and left arecord recording into the unlinked raw
file for ~76 minutes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 5 insertions, 1 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 770be39..4aef988 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -303,6 +303,10 @@ drives `arecord` on/off, clip POSTed to `/inference`.
   `prctl(PR_SET_PDEATHSIG, SIGTERM)` via ctypes in `preexec_fn`: they die
   with the assistant even on SIGKILL or a kill during startup (tested).
   Python's default SIGTERM skips `finally`; a handler calls `sys.exit`.
+- 2026-09-28: `arecord` lacked it. The assistant died with no log line
+  (last: "ready, mic is on", cause unknown) and left `arecord` recording
+  into the unlinked raw file for ~76 min. It now gets `die_with_parent`
+  too (not yet tested live); `assistant.sh status` lists a stray one.
 - Gemma confidently gave a wrong fact (a city-to-city distance off by
   ~10x). No tools yet, so no time/weather/facts lookup.
 - Recordings live in `$XDG_RUNTIME_DIR` and are deleted on exit.
diff --git a/assistant.py b/assistant.py
index 2a84cd6..a6d83f4 100644
--- a/assistant.py
+++ b/assistant.py
@@ -661,7 +661,7 @@ def main():
                 # default (~125 ms) left the user's waves at 8 levels a second.
                 rec = subprocess.Popen(["arecord", "-q", "-t", "raw", "-f", "S16_LE", "-r", "16000",
                                         "-c", "1", "--period-time=33333", RAW],
-                                       stderr=subprocess.DEVNULL)
+                                       stderr=subprocess.DEVNULL, preexec_fn=die_with_parent)
                 threading.Thread(target=user_levels, args=(rec, turn), daemon=True).start()
             elif rec:
                 rec.send_signal(signal.SIGINT)