Resume uses stale session pointer and reports "conversation history is no longer on disk" despite other project transcripts existing

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Session started at 3:39 AM; process died uncleanly (sleep/reboot/crash). The socket at /tmp/cc-socks/70651.sock was cleared, but ~/.claude/sessions/70651.json persisted as a dangling pointer. The .jsonl transcript was never flushed to disk before the process died.

Result: Claude Code reads the stale session registry, finds no matching .jsonl, and reports "conversation history is no longer on disk" — alarming and misleading because other project transcripts were present and readable.

What Should Happen?

Either: (a) flush transcript incrementally during the session rather than only at clean close, or (b) silently skip stale session pointers and offer the session picker — the error message "conversation history is no longer on disk" is misleading when other project transcripts exist.

Error Messages/Logs

"This session's conversation history is no longer on disk. You can keep working here — sending your message will start a fresh session in this folder."

Stale session file (~/.claude/sessions/70651.json):
{
  "pid": 70651,
  "sessionId": "c9106579-57de-4374-a5e1-fc7f5322738f",
  "procStart": "Wed Sep  9 03:39:01 2026",
  "version": "2.1.226",
  "entrypoint": "cli",
  "messagingSocketPath": "/tmp/cc-socks/70651.sock"
}

Missing transcript:
~/.claude/projects/-Users-...-Desktop-Bupropion/c9106579-57de-4374-a5e1-fc7f5322738f.jsonl

Other recent transcripts in same project dir: PRESENT

Steps to Reproduce

1. Start a CLI session (claude) in a project folder
2. Leave session running overnight (machine sleeps or reboots)
3. Process is killed uncleanly (no graceful shutdown)
4. Reopen Claude Code and attempt to resume the session
5. Receive "conversation history is no longer on disk" message

Key detail: ~/.claude/sessions/<pid>.json persists across reboots, but the matching .jsonl transcript was never written because the process died before flushing it. The socket /tmp/cc-socks/<pid>.sock is cleared on reboot; the session registry file is not.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.226

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

CLI version: 2.1.226 (claude --version). Desktop-app session metadata shows 2.1.260 — version mismatch worth investigating.

Workaround: claude --resume <known-good-session-id> or claude --resume (picker) to bypass the stale pointer.

Note: GitHub flagged #76829 ("Session transcript never created") as potential duplicate.