What
A directory whose cloud-session record was written by the older rows or archive sync engines will no longer resume syncing. Attaching to such a session shows a line beginning "File sync is off for this session here" and tells you to start a new cloud session from that directory. This applies to everyone on this build; no switch guards it.
Details
- The record reader used to return
rows,unseededandarchivealongsidegit; it now returns an "unsupported" result naming the engine, and any engine it does not recognise gets the same treatment. The stringarchiveno longer appears in the bundle. - Attach registers a stopped engine with reason
engine_unsupported, and the running loop reports the same. - Backing that stopped state is a do-nothing engine (activate, messageSent, afterResult, laneChanged, afterConnect, afterDisconnect all empty; send and drain resolve empty) plus a one-shot gate that answers "do not send" once with the reason, so the first message explains itself rather than failing silently.
Evidence
File sync is off for this session here: its local record was written by a sync engine this version of Claude Code does not have. Start a new cloud session from this directory to sync it., sync engine this version of Claude Code does not have
Strings lifted out of the shipped bundle, so the claim above can be checked against them.