fix(distill): detach bg pipeline with setsid so it survives session teardown#322
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…eardown
The distill bg pipeline was spawned as a disowned subshell, which stays in
the hook's process group/session. When the parent Claude session is torn
down as a group (ssh-driven maintenance sessions, CLI teardown), the
pipeline is killed before it can log anything — observed fleet-wide on
2026-07-07: gwakga/nosuk sessionend runs ended at "spawned bg" with no
done/skip/error line and stale distill-last.json. disown/nohup only guard
against SIGHUP, not group-targeted kills.
Fix: extract the pipeline body into run_bg_pipeline() and re-invoke the
script via `setsid bash distill.sh` with CLAUDE_DISTILL_BG=1 (new session,
immune to group teardown). Where setsid is unavailable, fall back to the
legacy disowned subshell. Inputs flow through the existing CLAUDE_DISTILL_*
env contract in both modes; the bg re-entry is checked before any hook-input
parsing and does not set INFLIGHT itself, so the recursion guard still
protects the nested `claude -p` session.
Evidence:
- claude/hooks/distill-scope.test.sh: 18/18 PASS
- PG-kill simulation: spawn hook via setsid, `kill -KILL -$$` immediately
after hook exit while stub extract sleeps 2s -> pipeline completes
("dry-run skipping ... elapsed_s=2"). Same scenario reproduced the
silent death with the old spawn.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
seoseo-ai
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Jul 7, 2026
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LGTM — distill bg pipeline setsid detach. Evidence: distill-scope.test.sh 18/18 PASS + PG-kill simulation survival (pipeline completes while parent group SIGKILLed mid-extract). Recursion-guard ordering (BG re-entry before INFLIGHT self-export) verified in review.
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What
distill.sh의 bg 파이프라인 spawn을 disowned subshell →
setsidself re-entry(신규 세션)로 교체. setsid 미가용 환경은 기존 subshell fallback 유지.Why
2026-07-07 fleet 점검에서 gwakga/nosuk의 sessionend distill이
spawned bg로그 후 done/skip/error 없이 무로그 사망 (distill-last.json stale). 원인: ssh 유지보수 세션 teardown이 프로세스 그룹째 kill → disown/nohup은 SIGHUP만 방어, group-kill 미방어.How
run_bg_pipeline()로 추출 (CLAUDE_DISTILL_* env 계약은 기존과 동일)CLAUDE_DISTILL_BG=1 setsid bash distill.sh <trigger>로 재진입 — 재진입 체크는 hook-input 파싱 이전, INFLIGHT는 파이프라인이 스스로 export하므로 recursion guard 유지mode=setsid|subshell추가 (기존spawned bggrep 계약 유지)Evidence
claude/hooks/distill-scope.test.sh: 18/18 PASSkill -KILL -$$(stub extract sleep 2s 중) → 파이프라인 완주(dry-run skipping ... elapsed_s=2). 구 코드 시나리오 재현으로 silent death 확인됨.Wiki: LOG-1509 후속 (memory-pipeline fleet 점검)
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