{"version":"2.1.301","anchor":"debug-log-routing-and-v5-storage-warnings","canonical_anchor":"debug-log-file-writing-now-disabled-for-diskless-sessions-vi","heading":"Debug log writing: diskless sessions stop writing files, and v5 storage warnings are more specific","tier":"notice","area":"Debug Logs","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.301\/e\/debug-log-routing-and-v5-storage-warnings","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.301","markdown":"### Debug log writing: diskless sessions stop writing files, and v5 storage warnings are more specific\n\nDiskless sessions no longer write debug log files even with CLAUDE_CODE_DEBUG_LOGS_DIR set, and the debug logger and v5 storage warnings change\n\n**Unclear.** What turns on skipping backend lines in the debug log is not stated.\n\n**What**\n\nClaude 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.\n\n- 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.\n\n- 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.\n\n- 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.\n\n- 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`.\n\nBefore this release, an error in the diskless check already led to no files being written, so the main difference is the earlier, explicit check.\n\n**Why**\n\nIf 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.\n\n- Area: Debug Logs\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 3\/5\n- Scope: individual\n- Heads-up: no"}