What probably matters to youSection of the release
What
Sandbox startup moved into its own step that can decline to launch. If the setting sandbox.failIfUnavailable is on and no working sandbox is found, Claude Code writes an error to stderr and exits with code 1. The setting defaults to false, in which case it logs a warning and records one setup issue instead. Remote sessions skip the check entirely.
Details
The setting is marked restrictive in the settings schema, so it can be enforced from a managed settings file.
When startup is refused, the remaining session startup steps are skipped.
