C# Interactive: Execution fails silently

Problem

Executing code in the C# Interactive from a scratch file fails silently when attempting to use the Send selection to C# interactive option.

Cause

C# Interactive in Rider requires the csi tool (C# scripting interactive tool) to function. On macOS, this tool is typically included with Mono or can be installed as a global .NET tool.

Without the csi tool available, Rider does not display an error message, and the command fails silently.

Resolution

1. Verify C# Interactive Setup in Rider:

   • Navigate to Settings | Languages & Frameworks | C# Interactive.
   • Check if any valid csi tool options are listed.

2. Install the C# Interactive Tool:

   • Mono Installation (includes csi):
     • Visit Mono’s website and complete the installation process.
   • Global .NET Tool Installation:

     • Run the following command to install dotnet-csi as a global tool:

       dotnet tool install --global dotnet-csi
       

3. Configure Rider:

   • After installation, configure the C# Interactive tool in Rider settings to point to the correct executable (csi or csi.exe):

Once the required tool is installed and configured, the C# Interactive feature should function as expected.

If further issues arise, collect the following information:

• Example scratch file that reproduces the issue.
• Recording of the reproduction steps.
• Rider diagnostics logs (Help | Collect Logs and Diagnostic Data).
• Share the generated archive and any other relevant details with JetBrains Support.