Crash in resume picker: TypeError: Cannot read properties of undefined (reading 'trim')

Summary

The interactive resume picker (claude --resume) crashes with TypeError: Cannot read properties of undefined (reading 'trim') when the session list contains entries that are "continued from a previous conversation" (i.e. auto-compaction continuations). The crash fires repeatedly on every keystroke / render, making the picker unusable.

This update genuinely broke my ability to get back to work — filing alongside #51842 (the related UX gap where there's no in-app resume path at all).

Reproduction

1. Work long enough in a session that context auto-compacts, producing "This session is being continued from a previous conversation that ran out of context. The summary below covers the earlier p…" entries.
2. Quit Claude Code.
3. From the project directory, run claude --resume.
4. Picker renders with ~8 continuation entries, all sharing that same truncated summary prefix.
5. Pressing arrow keys / trying to select any entry (or sometimes just opening the picker) throws the stack trace below, repeated many times per render cycle.

Stack trace

TypeError: Cannot read properties of undefined (reading 'trim')
    at nh6 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1708:4403)
    at pw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:72:19414)
    at Mt (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:42806)
    at b9 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:38347)
    at Up (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:38275)
    at B$ (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:38129)
    at Mz (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:35208)
    at ZQ (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:72:4840)
    at J5 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:74:32453)
    at Q.updateContainer (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:78:1827)

Likely cause: nh6 in cli.js:1708 calls .trim() on a field (probably the first user message / title) that is undefined for continuation sessions, because the "continued from previous" entries don't have a user message in the usual slot.

Workaround

Resume by explicit session ID, bypassing the picker entirely:

claude --resume <session-uuid-from-~/.claude/projects/>

This works, which confirms the crash is purely in the picker's render/formatting code — the underlying session data is fine.

Environment

• Claude Code: 2.0.33
• Node: v25.6.0
• OS: macOS 15.6.1 (Darwin 24.6.0, ARM64)
• Install: /opt/homebrew/lib/node_modules/@anthropic-ai/claude-code

Impact

Blocks resume from the interactive picker for any user whose sessions have auto-compacted (i.e. any long-running work). Combined with the lack of an in-app resume flow (#51842), it's a rough experience after an update.