Regression in 1.0.49: long startup and post-approval blocking in WSL

[whitebob]

Summary

After upgrading to Copilot CLI 1.0.49, the CLI became significantly slower in a WSL Linux terminal. This did not happen before 1.0.49.

Environment

• Copilot CLI: 1.0.49
• Environment: WSL Linux terminal
• GitHub auth available via gh

Symptoms

• Startup blocks for about 2 minutes before the UI becomes responsive.
• After approving a local command with Yes, there is another noticeable blocking delay before the command actually starts executing.
• In some cases there is no visible progress output or useful log output during the delay.

What I tried

• Disabled built-in GitHub MCP server
• Disabled skills
• Disabled hooks
• Disabled IDE auto-connect

The delays still happen, although MCP/auth/tool initialization seems strongly related to the slowdown.

Observations

• The issue appears to be in the orchestration/initialization path rather than the shell command itself.
• Running local commands directly in the shell is instantaneous.
• The slowdown feels related to remote/tooling/auth initialization, which may be especially noticeable in WSL.

Reproduction

1. Start Copilot CLI in WSL.
2. Wait for initial startup.
3. Ask Copilot to run a simple local command.
4. Approve the command with Yes.
5. Observe the long blocking delay before the command actually starts.

Expected behavior

• Startup should be fast, similar to pre-1.0.49 behavior.
• After approving a local command, execution should begin immediately or show clear progress/debug information.

Actual behavior

• Startup and post-approval execution both have large blocking delays.
• The CLI feels much heavier than before 1.0.49 in WSL.

Request

Please investigate whether a regression was introduced in 1.0.49 around:

• MCP/auth initialization
• remote orchestration before local command execution
• WSL-specific terminal/flush latency
• startup path regressions with minimal/local-only configurations

It would also help to have:

• a strict local/fast path mode
• better debug/verbose output for startup and pre-command blocking

[whitebob]

Additional feedback: Copilot CLI was strongest when it stayed focused on fast, reliable command-line orchestration and local coding workflows. From a user perspective, features like built-in MCP and skills currently feel like they add platform and initialization overhead without improving the core CLI experience in WSL. In my case, they make the product feel heavier and less responsive, which cuts against the main reason to use a terminal-native tool in the first place. I would strongly prefer the product to prioritize local performance, command approval-to-execution latency, and a clear fast path for shell/file/code workflows over broader remote capability layers.

[reillysiemens]

I'm experiencing a similar regression in performance with the upgrade from 1.0.48 to 1.0.49 in my own WSL instances.

[carter003]

#3385

[maaslalani]

Thank you so much for the report. We identified the root cause and merged the fix. The fix will be available in the next release.

[maaslalani]

The fix is available in the pre-release as well: https://github.com/github/copilot-cli/releases/tag/v1.0.51-2