You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Headless ModeArea: what it touches
ImprovementsKind: in v2.1.317,
ImprovementsSection of the release
What
Print mode is the way to run Claude Code once from a script, with claude -p, instead of in an interactive chat. When such a run ends, Claude Code now checks whether any writes were lost because the disk was full (ENOSPC) or a disk quota was used up (EDQUOT). It checks two kinds of write:
the session transcript, which is the saved record of the conversation
~/.claude.json
If writes were lost:
An error is written to stderr, the error output stream.
Runs with stream-json output also get a system message with the subtype session_writes_lost.
Runs with any other output format exit with code 1, which scripts treat as a failure.
The check is skipped for runs started with --sdk-url. The message is never sent there or in Claude Desktop. The check sits behind a remote switch whose built-in default is on, so it applies unless it is switched off remotely.
Why
Before, lines could be dropped from the transcript without any sign. Scripts that run claude -p can now notice when a full disk caused this.
Read from
Feature flag
tengu_rosy_crabNot enough to say
Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.317: on
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's release notes agreeAdded CLAUDE_CODE_DISABLE_NESTED_SESSION_ID: set it to 1 on a self-hosted runner to have claude -p run inside a session use that session's…
The name it cites is new in this buildNew in this build: tengu_rosy_crab
