You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Diskless SessionsArea: what it touches
ImprovementsKind: in v2.1.301,
ImprovementsSection of the release
What
Claude Code can write a debug log, a detailed record of what it is doing, to a file. Several parts of how that log is written changed.
A diskless session (one set up not to write files to disk) now never writes debug log files, even when CLAUDE_CODE_DEBUG_LOGS_DIR is set. A new check, isSessionDiskless(), makes this decision. If that check fails with an error, the session is treated as diskless.
The debug-log grouping now returns nothing for diskless sessions, unless storageV5 is set and neither a file path nor CLAUDE_CODE_DEBUG_LOGS_DIR is configured.
The debug logger now skips lines that came from the backend when a flag is set, and sends the remaining lines to a fixed destination.
The warning shown when the v5 storage backend is not used gains a second message for when the config home was absent: "The v5 storage backend is not used: the config home was". Before, there was a single message about CLAUDE_CONFIG_DIR.
Before this release, an error in the diskless check already led to no files being written, so the main difference is the earlier, explicit check.
Why
If you run sessions that are meant to leave nothing on disk, debug logs now stay out of files even when a log location is configured. The v5 storage warning now says more precisely why that storage was not used.
