[.NET] Bundled Copilot Cli download times out

[lbussell]

Steps to repro

Follow the getting started guide.

0. macOS 26 (Arm64)
1. dotnet new console -n $whatever -o $wherever
2. Add to .csproj:

   <ItemGroup Label="Dependencies">
     <PackageReference Include="GitHub.Copilot.SDK" Version="0.1.24-preview.0" />
   </ItemGroup>

3. Copy-paste in the example code from getting started guide (permalink)
4. Run dotnet run -v diag

Error message:

CopilotPlayground % dotnet run -v diag
Restore complete (0.2s)
    Determining projects to restore...
    All projects are up-to-date for restore.
  CopilotPlayground net10.0 failed with 1 error(s) (100.1s)
    Downloading Copilot CLI 0.0.405 for darwin-arm64...
    /Users/loganbussell/.nuget/packages/github.copilot.sdk/0.1.24-preview.0/build/GitHub.Copilot.SDK.targets(47,5): error MSB3923: Failed to download file "https://registry.npmjs.org/@github/copilot-darwin-arm64/-/copilot-darwin-arm64-0.0.405.tgz".  The request was canceled due to the configured HttpClient.Timeout of 100 seconds elapsing. ---> A task was canceled. ---> A task was canceled.

Build failed with 1 error(s) in 100.5s

The build failed. Fix the build errors and run again.

When I download the tarball from the link using my browser, it works no problem (instantly) https://registry.npmjs.org/@github/copilot-darwin-arm64/-/copilot-darwin-arm64-0.0.405.tgz.

[github-actions]

Thanks for reporting this, @lbussell! I've labeled this as a bug with the .NET SDK.

The issue is clear: the bundled CLI download times out after 100 seconds when building on macOS arm64, even though the same file downloads instantly in a browser. This appears to be an issue with the MSBuild download task's HttpClient timeout or network configuration.

This should be investigated by the maintainers.

AI generated by Issue Triage Agent

[lbussell]

Also, version 0.1.23 works fine.