Chrome native host crashes on startup (Bun assertion failure) — Windows 11

Description

claude.exe --chrome-native-host crashes immediately on startup with a Bun internal assertion failure on Windows 11. This prevents the Chrome extension from connecting to Claude Code — the named pipe (\\.\pipe\claude-mcp-browser-bridge-User) is never created.

The error message shown to the user is the generic "Browser extension is not connected" with no indication that the native host is crashing.

Environment

• Claude Code version: 2.1.97
• OS: Windows 11 Pro 10.0.26200
• Bun version (bundled): 1.3.11

Steps to Reproduce

1. Install Claude Code on Windows 11
2. Install the Claude browser extension in Chrome
3. Run any Claude Code session and attempt to use Chrome tools
4. Observe "Browser extension is not connected" error

Running the native host manually shows the crash:

> "C:\Users\User\.claude\chrome\chrome-native-host.bat"

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \\.\pipe\claude-mcp-browser-bridge-User

panic(main thread): Internal assertion failure
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Bun Crash Report

https://bun.report/1.3.11/e_187b3dffEkgggC+or/M+ky6G6izmoBqqqgoB__uo5h5CA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg

Additional Context

• Registry entry at HKCU\Software\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_code_browser_extension is correctly configured
• The native host JSON manifest at C:\Users\User\AppData\Roaming\Claude Code\ChromeNativeHost\com.anthropic.claude_code_browser_extension.json is correct
• Chrome extension (v1.0.66) is installed and enabled
• The bat wrapper at C:\Users\User\.claude\chrome\chrome-native-host.bat correctly invokes claude.exe --chrome-native-host
• Everything is wired up properly — the crash happens inside the Bun runtime before the pipe can be established
• Claude Desktop (Cowork) native host config was disabled to rule out the known conflict between Cowork and Claude Code native messaging hosts

Suggestion

A more descriptive error message when the native host fails to start (e.g., "Native host process crashed" with a pointer to logs) would significantly reduce debugging time compared to the current generic "not connected" message.