SessionStart hooks have no explicit timeout — a stall blocks session start for 10+ minutes

Summary

hooks/hooks.json registers three SessionStart commands with no timeout field, so each inherits Claude Code's 600-second default. When one of them stalls, session start blocks for the full ten minutes before the timeout fires.

Evidence

Three hook_cancelled transcript entries, all with timedOut: true:

{"hookName": "SessionStart:resume", "hookEvent": "SessionStart",
 "durationMs": 961095, "timedOut": true, "timeoutMs": 600000}

961 s elapsed against a 600 s timeout, on session resume.

Environment

• Plugin vercel@claude-plugins-official v0.45.1
• Claude Code 2.1.220 (native install), macOS
• Node v18.20.8; hooks resolve node from /opt/homebrew/bin/node

Notes

Intermittent — the hooks normally complete quickly (~/.config/vercel-plugin/dau-stamp and active-session.json are written on most sessions). I could not identify the stalling script from reading the source. Two plausible suspects are ruled out: sendTelemetry in telemetry.mjs already bounds its fetch with a 3 s AbortController, and the readdirSync calls in session-start-profiler.mjs are single-level rather than recursive.

One environmental note that may or may not be relevant: the project root in my case is the home directory, so session-start-profiler.mjs runs readdirSync against $HOME.

Suggested fix

Set an explicit short timeout on each SessionStart hook in hooks.json — 10–15 s seems ample given normal completion time. A session-start hook inheriting the 600 s default means any stall is a ten-minute block. I've patched this locally, but a plugin update will overwrite it.

Open hooks/hooks.json and inspect the three SessionStart command registrations; the issue identifies the missing timeout fields and suggests a 10–15 second limit. Add an explicit timeout to each hook, then verify that all three registrations have the intended bound and do not inherit the 600-second default.