[BUG] Auto-update leaves installation in broken state with incomplete package files

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?

After accepting the auto-update prompt (from ~2.1.1 to 2.1.2), Claude Code stopped working. Running claude or claude update produces:

/Users/jetbrains/.claude/local/claude: line 2: /Users/jetbrains/.claude/local/node_modules/.bin/claude: No such file or directory
/Users/jetbrains/.claude/local/claude: line 2: exec: /Users/jetbrains/.claude/local/node_modules/.bin/claude: cannot execute: No such file or directory

Investigation revealed:

1. The symlink in ~/.claude/local/node_modules/.bin/ was named .claude-4RefIwJ (temporary name) instead of claude
2. The @anthropic-ai/claude-code/ directory contained only a vendor folder - missing cli.js and all other package files

The auto-updater appears to have been interrupted mid-process, leaving both the symlink rename and package extraction incomplete.

What Should Happen?

Auto-update should either complete fully or rollback to the previous working state. The installation should never be left in a broken state where the CLI is unusable.

Error Messages/Logs

/Users/jetbrains/.claude/local/claude: line 2: /Users/jetbrains/.claude/local/node_modules/.bin/claude: No such file or directory
/Users/jetbrains/.claude/local/claude: line 2: exec: /Users/jetbrains/.claude/local/node_modules/.bin/claude: cannot execute: No such file or directory

Steps to Reproduce

1. Have Claude Code installed via the local installation method (~/.claude/local/)
2. Accept the auto-update prompt when a new version is available
3. (Uncertain what triggers the failure - possibly network interruption or timing issue during update)
4. After update completes, run claude - command fails

To verify the broken state:

• ls -la ~/.claude/local/node_modules/.bin/ shows temporary symlink name like .claude-4RefIwJ instead of claude
• ls -la ~/.claude/local/node_modules/@anthropic-ai/claude-code/ shows only vendor directory, missing cli.js

Workaround: cd ~/.claude/local && rm -rf node_modules package-lock.json && npm install

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.1 (approximately)

Claude Code Version

2.1.2 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

The issue suggests the auto-updater lacks atomic update guarantees. Potential improvements:

• Use atomic rename for symlinks
• Verify package integrity before removing old version
• Implement rollback on failure

Screenshots attached showing the broken symlink name and incomplete package directory.

<img width="80%" alt="Image" src="https://github.com/user-attachments/assets/58b590d7-8ab9-4097-ae38-4dcfd47b2971" />