Command.Result blocks indefinitely in xunit

I have been debugging this for a while and finally found a cause of my tests blocking on xunit.

I’ve been writing a simple xunit test:

using Medallion.Shell;

namespace TestProject1;

public class UnitTest1
{
    [Fact]
    public void Test1()
    {
        const string consoleAppPath = @"T:\Temp\ConsoleApp99";
        const string consoleAppProjectFileName = @"ConsoleApp99.csproj";

        Console.WriteLine(
            Command.Run("dotnet", new[] { "build", "--configuration", "Release", Path.Combine(
                consoleAppPath, consoleAppProjectFileName) }, o=> o.WorkingDirectory(consoleAppPath)).Result.StandardOutput
        );
    }
}

This blocks indefinitely on Result (not on StandardOutput!), even if I kill dotnet build and all the child processes manually.

xunit is known for its sync context, so probably there’s a ConfigureAwait(false) missing somewhere.

(I wouldn’t ask for this in general, but it’s a good idea to use that if you provide a synchronous API.)

[ForNeVeR]

At least I’ve figured out that this issue is definitely unrelated to MedallionShell, so I’ve posted it to .NET SDK issue tracker: https://github.com/dotnet/sdk/issues/34653

Still no idea whatever happens there, but let’s at least free MedallionShell of this burden for now.

[ForNeVeR]

1. Earlier, I was testing on .NET 8, but just found that .NET 7 is also affected.

   And this is unlikely to be a bug in Medallion.Shell. But I have no repro without it, and thus will investigate further.

2. Reproduces on async test as well 😱

   using Medallion.Shell;
   
   namespace TestProject2;
   
   public class Tests
   {
       [SetUp]
       public void Setup()
       {
       }
   
       [Test]
       public async Task Test1()
       {
           const string consoleAppPath = @"G:\Projects\Medallion.Shell.Bug104\ConsoleApp99";
           const string consoleAppProjectFileName = @"ConsoleApp99.csproj";
   
           ThreadPool.GetMaxThreads(out var w, out var t);
           
           Console.WriteLine("threads worker " + w);
           Console.WriteLine("threads completion pool " + t);
   
           Console.WriteLine(SynchronizationContext.Current?.ToString());
           Console.WriteLine(TaskScheduler.Current.ToString());
   
           var result = await Command.Run("dotnet", new[] { "build", "--configuration", "Release", Path.Combine(
                   consoleAppPath, consoleAppProjectFileName) }, o=> o.WorkingDirectory(consoleAppPath)).Task;
           Console.WriteLine(
               result.StandardOutput
           );
       }
   }