Running benchmarks hangs at "// Validating benchmarks:" when you have many, many SDKs installed

[thatnerdyguy]

If you have many, many SDKs installed (in our case 89 ... this is from a localized dotnet install via the UseDotNet task in devops pipelines), and then attempt to run benchmarks, you get stuck at the

// Validating benchmarks:

Bringing up ProcessMonitor, we could see the host benchmark executable was waiting on

dotnet --list-sdks

to finish. We assume from DotNetSdkValidator.GetInstalledDotNetSdks(). That function does:

process.WaitForExit();
// stuff
var output = process.StandardOutput.ReadToEnd();

However, per the docs (https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.processstartinfo.redirectstandardoutput?view=net-9.0#remarks) that approach will deadlock when the stdout buffer gets full. Instead you want to:

var output = process.StandardOutput.ReadToEnd();
process.WaitForExit();

[timcassell]

It looks like we do the correct thing everywhere except here.

BenchmarkDotNet/src/BenchmarkDotNet/Validators/DotNetSdkValidator.cs

Line 68 in d2be797

private static IEnumerable<Version> GetInstalledDotNetSdks(string? customDotNetCliPath)

Accepting PRs.

[filzrev]

It seems following code also has issue that similar to reported issue.
Because RedirectStandardError=true but is not consumed.

BenchmarkDotNet/src/BenchmarkDotNet/Helpers/ProcessHelper.cs

Lines 15 to 46 in d2be797

	internal static string? RunAndReadOutput(string fileName, string arguments = "", ILogger? logger = null,
	Dictionary<string, string>? environmentVariables = null)
	{
	var processStartInfo = new ProcessStartInfo
	{
	FileName = fileName,
	WorkingDirectory = "",
	Arguments = arguments,
	UseShellExecute = false,
	CreateNoWindow = true,
	RedirectStandardOutput = true,
	RedirectStandardError = true
	};
	if (environmentVariables != null)
	foreach (var variable in environmentVariables)
	processStartInfo.Environment[variable.Key] = variable.Value;
	using (var process = new Process { StartInfo = processStartInfo })
	using (new ConsoleExitHandler(process, logger ?? NullLogger.Instance))
	{
	try
	{
	process.Start();
	}
	catch (Exception)
	{
	return null;
	}
	string output = process.StandardOutput.ReadToEnd();
	process.WaitForExit();
	return output;
	}
	}