You'll noticeTier: how much it should matter to you
4Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Headless ModeArea: what it touches
Bug FixesKind: in v2.1.227,
What probably matters to youSection of the release
What
Failures writing to the output stream, and rejections from a headless run, no longer end the process silently. Claude now prints a truncated human-readable reason to stderr, emits it as a stream-json message where applicable, and exits with code 1.
Details
A tengu_headless_fatal_error event records where the failure happened, the message type, the control subtype, how many messages had been drained, how many stdout bytes were still outstanding, and whether stdout had already been destroyed.
Applies to every headless (-p) run, no flag required.
Evidence
tengu_headless_fatal_error
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
