When a session or worker restarts, Claude Code now shows a targeted message instead of a generic one:
- "Agent is updating to the new Claude Code…" — when the restart is due to a software update (ERESPAWNING + "updated"/"upgrad")
- "Session not responding — restarting it…" — when the worker stalled
- "Migrating job to attachable PTY…" — for legacy job PTY migration
- "Session is restarting…" — generic fallback
Evidence
Restart message strings (search for "Agent is updating to the new Claude Code") — Bv_() at line ~718756
Strings lifted out of the shipped bundle, so the claim above can be checked against them.