[BUG] z is not iterable

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?

Environment:

• Claude Code CLI: v2.1.75
• VS Code: WSL (Ubuntu)
• Extension: Claude Code for VS Code (latest from marketplace)

Issue:
The Claude Code sidebar panel shows "z is not iterable" error and fails to load.
The CLI works fine in the integrated terminal.

Steps:

1. Open VS Code connected to WSL
2. Open Claude Code panel in sidebar
3. Error appears: "z is not iterable"

Tried:

• npm update + reload window
• Uninstall npm version, reinstall via native installer (curl)
• Reinstall extension
• Developer: Reload Window

CLI works perfectly in terminal, only the sidebar panel is broken.

What Should Happen?

Environment:

• Claude Code CLI: v2.1.75
• VS Code: WSL (Ubuntu)
• Extension: Claude Code for VS Code (latest from marketplace)

Issue:
The Claude Code sidebar panel shows "z is not iterable" error and fails to load.
The CLI works fine in the integrated terminal.

Steps:

1. Open VS Code connected to WSL
2. Open Claude Code panel in sidebar
3. Error appears: "z is not iterable"

Tried:

• npm update + reload window
• Uninstall npm version, reinstall via native installer (curl)
• Reinstall extension
• Developer: Reload Window

CLI works perfectly in terminal, only the sidebar panel is broken.

Error Messages/Logs

The Claude Code sidebar panel should load and function normally, allowing conversation and interaction just like the terminal CLI.

Steps to Reproduce

Environment:

• Claude Code CLI: v2.1.75
• VS Code: WSL (Ubuntu)
• Extension: Claude Code for VS Code (latest from marketplace)

Issue:
The Claude Code sidebar panel shows "z is not iterable" error and fails to load.
The CLI works fine in the integrated terminal.

Steps:

1. Open VS Code connected to WSL
2. Open Claude Code panel in sidebar
3. Error appears: "z is not iterable"

Tried:

• npm update + reload window
• Uninstall npm version, reinstall via native installer (curl)
• Reinstall extension
• Developer: Reload Window

CLI works perfectly in terminal, only the sidebar panel is broken.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.75

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_