[BUG] claude update reports success but never installs new version (Windows, ESAI NuGet distribution)

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?

Summary

claude update reports "Successfully updated from 2.1.92 to version 2.1.100" but no new version is created. The CurrentVersion symlink remains pointed at the old version. Repeatable across sessions — new
shells still show 2.1.92.

## Environment

• OS: Windows 11 Pro for Workstations 10.0.26200.7985
• Install method: Microsoft ESAI NuGet feed (Anthropic.Claude.CLI.win-x64 package)
• Install location: C:\Users\<user>\.claude-cli\
• Current version: 2.1.92
• Node: v22.16.0, npm 11.7.0
• PATH entries: .claude-cli/CurrentVersion (symlink → 2.1.92/)

## Repro steps

1. Open a terminal (no other claude instances running)
2. Run claude update
3. Observe output:

``
Current version: 2.1.92
Checking for updates to latest version...
Successfully updated from 2.1.92 to version 2.1.100
``

1. Open a new terminal (new shell process)
2. Run claude --version → still shows 2.1.92
3. Run claude update again → same "Successfully updated" message, still 2.1.92

## Observed state

``
C:\Users\<user>\.claude-cli\
├── 2.1.86/
├── 2.1.90/
├── 2.1.92/
│ ├── claude.exe (240 MB, dated 2026-04-06)
│ ├── Anthropic.Claude.CLI.win-x64.nuspec (version: 2.1.92)
│ ├── [Content_Types].xml
│ ├── _rels/
│ └── package/
└── CurrentVersion -> C:\Users\<user>\.claude-cli\2.1.92\
``

No 2.1.100 folder is ever created. The update claims success but produces no artifacts.

## Expected behavior

After claude update:

1. A 2.1.100/ folder should be created with the new claude.exe
2. The CurrentVersion symlink should be updated to point to 2.1.100/
3. New shell sessions should resolve claude --version as 2.1.100

## Additional context

• The .nuspec shows this is the ESAI feed distribution (owners: Microsoft ESAI), not npm or direct download
• where claude returns nothing (not on PATH as a standard exe — resolved via the CurrentVersion symlink in PATH)
• npm list -g @anthropic-ai/claude-code shows empty — not installed via npm
• npx @anthropic-ai/claude-code@latest runs ephemerally but does not update the .claude-cli installation
• No logs found in ~/.claude/logs/ or ~/.claude/*.log
• Previous updates (2.1.86 → 2.1.90 → 2.1.92) worked correctly based on folder timestamps

## Hypothesis

The claude update command may be designed for the npm install path and doesn't know how to update the NuGet/ESAI distribution. It detects a newer version exists, prints success, but never
downloads/extracts the binary or updates the symlink.

What Should Happen?

It should update

Error Messages/Logs

No Error

Steps to Reproduce

claude update 2x and see same version both times

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.92

Claude Code Version

2.1.92

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_