[BUG] VS Code extension v2.1.129 (win32-x64) fails to activate on Windows — hardcoded Linux build path

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?

The VS Code extension v2.1.129 (win32-x64) fails to activate on Windows. The extension panel (CLAUDE CODE tab) is completely blank/white after installing. Reinstalling the extension does not fix the issue.

The extension host log shows the following activation error:

TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received 'file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs'

A Linux build path (/home/runner/work/...) appears to have been hardcoded into the Windows build of the extension.

What Should Happen?

The extension should activate successfully and display the Claude Code interface in the VS Code panel.

Error Messages/Logs

From %APPDATA%\Code\logs\...\window1\exthost\exthost.log:

2026-05-06 12:46:13.101 [info] ExtensionService#_doActivateExtension Anthropic.claude-code, startup: false, activationEvent: 'onView:claudeVSCodeSidebarSecondary'
2026-05-06 12:46:13.176 [error] Activating extension Anthropic.claude-code failed due to an error:
2026-05-06 12:46:13.176 [error] TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received 'file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs'
	at Object.<anonymous> (c:\Users\ceo\.vscode\extensions\anthropic.claude-code-2.1.129-win32-x64\extension.js:102:5407)

Steps to Reproduce

1. Install Claude Code VS Code extension v2.1.129 (win32-x64) on Windows
2. Open VS Code and click the Claude Code panel
3. The CLAUDE CODE tab appears completely blank/white
4. Check exthost.log — extension fails to activate with the error above

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.128

Claude Code Version

2.1.129 (win32-x64)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_