Demo program for discussion of dotnet/cli#11016

Demo.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.1</TargetFramework>
  </PropertyGroup>

</Project>

Program.cs

using System;
using System.Collections;
using System.Diagnostics;
using System.Linq;

static class Program
{
    static int Main(string[] args)
    {
        var psi = new ProcessStartInfo(args[0])
        {
            UseShellExecute        = false,
            CreateNoWindow         = true,
            RedirectStandardOutput = true,
            RedirectStandardError  = true,
        };

        foreach (var arg in args.Skip(1))
            psi.ArgumentList.Add(arg);

        using (var process = Process.Start(psi))
        {
            process.OutputDataReceived += (_, ea) =>
            {
                if (ea.Data != null)
                    Console.WriteLine(ea.Data);
            };

            process.ErrorDataReceived += (_, ea) =>
            {
                if (ea.Data != null)
                    Console.Error.WriteLine(ea.Data);
            };

            process.BeginOutputReadLine();
            process.BeginErrorReadLine();

            process.WaitForExit();

            return process.ExitCode;
        }
    }
}