Windows: ucode copilot cannot launch npm-installed GitHub Copilot CLI

[deepak-databricks]

Summary

I’m seeing a Windows launch failure with ucode copilot when GitHub Copilot CLI is installed through npm.

What Works

• ucode starts successfully.
• Databricks authentication completes successfully.
• Unity AI Gateway detection and configuration complete successfully.

Steps to Reproduce

1. Install GitHub Copilot CLI through npm on Windows.
2. Configure ucode as usual.
3. Run:

   ucode copilot

Actual Behavior

ucode prints:

Starting GitHub Copilot CLI

It then exits with:

FileNotFoundError: [WinError 2] The system cannot find the file specified

The traceback points to subprocess.Popen(...) in ucode/agents/copilot.py, where ucode attempts to launch the bare command name copilot. The failure occurs before the Copilot CLI itself starts.

Expected Behavior

ucode copilot should resolve and launch the npm-installed GitHub Copilot CLI on Windows while preserving ucode’s environment, MCP configuration, Gateway settings, and token-refresh behavior.

Suspected Cause

On Windows, npm commonly exposes CLI commands through wrappers such as copilot.cmd and copilot.ps1, rather than a native copilot.exe. An interactive shell can resolve these wrappers, but Python’s direct process-creation path does not reliably resolve a .cmd shim when ucode passes copilot directly to subprocess.Popen with shell=False.

Suggested Fix

Could the Windows launcher resolve npm-installed commands with shutil.which() and invoke a .cmd shim through cmd.exe /d /c?

A reusable Windows helper for npm-based agents may also address the same issue for other CLI integrations. In particular, the launcher could:

1. Resolve copilot.cmd on Windows.
2. Use the resolved command for validation and launch.
3. Invoke the shim through cmd.exe /d /c rather than passing it directly to subprocess.Popen.

Environment

Component	Details
OS	Windows [version/build]
Shell	Git Bash / MINGW64
Python	3.13
ucode	[version or commit]
GitHub Copilot CLI	[version]
Copilot CLI Installation	npm [package/version]
ucode Installation	uv [version]

Additional Context

This may be related to existing Windows/PATHEXT handling issues. I’m reporting the specific ucode copilot failure separately because the repository documents Copilot CLI as a supported integration.

Attached Screenshots:

• Launch output
• Traceback