Runtime events: a slow handler can block the agent, and a handler can't tell which event fired #5336

#!/usr/bin/env bash
# u3: when an extension's runtime-event handler runs past its timeout, spec-kit's event runner exits 2.
# For Claude Code, exit 2 from a Stop hook means "block": the agent is told to keep going.
# The handler below stands in for any slow call (a network request, a lock wait) with `sleep`.
# Everything else is stock: a minimal extension declaring a documented `stop` event with a 2 second timeout.
set -uo pipefail
REF="${REF:-v1.2.6}"
WORK="$(mktemp -d)"
cd "$WORK"
SPECIFY=(uvx -q --from "git+https://github.com/github/spec-kit.git@$REF" specify)
"${SPECIFY[@]}" init --here --force --non-interactive --integration claude --script sh --ignore-agent-tools >/dev/null 2>&1 || { echo "init failed"; exit 2; }
echo "spec-kit $REF in $WORK"

mkdir -p ext/commands ext/scripts/bash
cat > ext/extension.yml <<'YML'
schema_version: "1.0"
extension:
  id: slowstop
  name: "Slow stop handler"
  version: "0.1.0"
  description: "Records something when a turn ends"
  author: repro
  repository: https://example.com/slowstop
  license: MIT
requires:
  speckit_version: ">=1.2.0"
provides:
  commands:
    - name: speckit.slowstop.record
      file: commands/speckit.slowstop.record.md
      description: "Record the turn end"
events:
  stop:
    command: speckit.slowstop.record
    timeout: 2
YML
cat > ext/commands/speckit.slowstop.record.md <<'MD'
---
description: "Record the turn end"
scripts:
  sh: scripts/bash/record.sh
---
Runs on its own when a turn ends.
MD
printf '#!/usr/bin/env bash\nsleep 5\necho recorded\n' > ext/scripts/bash/record.sh
chmod +x ext/scripts/bash/record.sh
"${SPECIFY[@]}" extension add --dev ./ext </dev/null 2>&1 | tail -1

hook=$(python3 - <<'PY'
import json
s=json.load(open(".claude/settings.json"))
for group in s.get("hooks",{}).get("Stop",[]):
    for h in group.get("hooks",[]):
        if "slowstop" in h.get("command","") or "events" in h.get("command",""):
            print(h["command"]); raise SystemExit
PY
)
echo "Stop hook spec-kit wrote into .claude/settings.json:"
echo "  $hook"
[ -n "$hook" ] || { echo "no Stop hook found; not reproduced"; exit 1; }
echo '{"session_id":"repro","hook_event_name":"Stop","stop_hook_active":false}' > payload.json
run_hook() {
  start=$(date +%s)
  CLAUDE_PROJECT_DIR="$WORK" bash -c "$hook" < payload.json > out.txt 2> err.txt
  code=$?
  secs=$(( $(date +%s) - start ))
}
echo "A. the handler finishes in time (sleep 1, timeout 2)"
printf '#!/usr/bin/env bash\nsleep 1\necho recorded\n' > .specify/extensions/slowstop/scripts/bash/record.sh
run_hook; echo "   ran ${secs}s, exit $code, stderr: $(cat err.txt)"
okcode=$code
echo "B. the handler runs past its timeout (sleep 5, timeout 2)"
printf '#!/usr/bin/env bash\nsleep 5\necho recorded\n' > .specify/extensions/slowstop/scripts/bash/record.sh
run_hook; echo "   ran ${secs}s, exit $code, stderr: $(cat err.txt)"
if [ "$okcode" = "0" ] && [ "$code" = "2" ] && [ "$(awk '/timed out/{n++} END{print n+0}' err.txt)" != "0" ]; then
  echo "RESULT: spec-kit's runner timed the handler out and exited 2; Claude Code reads exit 2 from a Stop hook as a block"; exit 0
fi
echo "RESULT: not reproduced on $REF (in-time exit $okcode, timeout exit $code)"; exit 1