NixOS issue with Csharp

[JeztC]

I get this error when trying to run Centria's csharp test runner. I have installed both dotnet runtime and dotnet sdk. Any idea why it won't work?

OS info:
OS: NixOS 23.11.2217.d02d818f22c7 (Tapir) x86_64
VSCodium Version: 1.84.2
TMC Extension Version: 3.0.2

Error:

"error": {
      "name": "Runtime Error",
      "details": "Caused by: Failed to run tests for exercise at /home/jesse/.local/share/tmc/vscode/centria-csharp-advanced-spring-24/part_08-001_nicknames\nCaused by: Failed to run command\nCaused by: The executable for command PATH='nixpkgxpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos:nixos-config=/etc/nixos/configuration.nix:/nix/var/nix/profiles/per-user/root/channels' dotnet /home/jesse/.cache/tmc/tmc-csharp-runner/TestMyCode.CSharp.Bootstrap.dll --run-tests could not be found. Please make sure you have installed it correctly.\nCaused by: No such file or directory (os error 2)\nCaused by: No such file or directory (os error 2)"
}

My dotnet info:

 Version:   6.0.418
 Commit:    21f869269c

Runtime Environment:
 OS Name:     nixos
 OS Version:  23.11
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /nix/store/kblvs7ymjvbmld4zcxcdvqbacjp3jm3w-dotnet-sdk-6.0.418/sdk/6.0.418/

global.json file:
  Not found

Host:
  Version:      6.0.26
  Architecture: x64
  Commit:       dc45e96840

.NET SDKs installed:
  6.0.418 [/nix/store/kblvs7ymjvbmld4zcxcdvqbacjp3jm3w-dotnet-sdk-6.0.418/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.26 [/nix/store/kblvs7ymjvbmld4zcxcdvqbacjp3jm3w-dotnet-sdk-6.0.418/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.26 [/nix/store/kblvs7ymjvbmld4zcxcdvqbacjp3jm3w-dotnet-sdk-6.0.418/shared/Microsoft.NETCore.App]

Download .NET:
  https://aka.ms/dotnet-download

Learn about .NET Runtimes and SDKs:
  https://aka.ms/dotnet/runtimes-sdk-info

The TMC-csharp-runner folder: