Make all command execution synchronous

- This fixes a bunch of weird races I was seeing building
larger solutions.

src/Microsoft.DotNet.Cli.Utils/Command.cs

@@ -11,7 +11,6 @@ namespace Microsoft.DotNet.Cli.Utils
 {
     public class Command
     {
-        private TaskCompletionSource<int> _processTcs;
         private Process _process;
 
         private StringWriter _stdOutCapture;
@@ -36,8 +35,6 @@ namespace Microsoft.DotNet.Cli.Utils
                 RedirectStandardOutput = true
             };
 
-            _processTcs = new TaskCompletionSource<int>();
-
             _process = new Process()
             {
                 StartInfo = psi
@@ -112,34 +109,37 @@ namespace Microsoft.DotNet.Cli.Utils
             return false;
         }
 
-        public async Task<CommandResult> RunAsync()
+        public CommandResult Execute()
         {
             ThrowIfRunning();
             _running = true;
 
             _process.OutputDataReceived += (sender, args) =>
+            {
                 ProcessData(args.Data, _stdOutCapture, _stdOutForward, _stdOutHandler);
+            };
 
             _process.ErrorDataReceived += (sender, args) =>
+            {
                 ProcessData(args.Data, _stdErrCapture, _stdErrForward, _stdErrHandler);
+            };
 
             _process.EnableRaisingEvents = true;
 
-            _process.Exited += (sender, _) =>
-                _processTcs.SetResult(_process.ExitCode);
-
 #if DEBUG
             var sw = Stopwatch.StartNew();
-            Reporter.Output.WriteLine($"> {_process.StartInfo.FileName} {_process.StartInfo.Arguments}".White());
+            Reporter.Output.WriteLine($"> {FormatProcessInfo(_process.StartInfo)}".White());
 #endif
             _process.Start();
             _process.BeginOutputReadLine();
             _process.BeginErrorReadLine();
 
-            var exitCode = await _processTcs.Task;
+            _process.WaitForExit();
+
+            var exitCode = _process.ExitCode;
 
 #if DEBUG
-            var message = $"> {_process.StartInfo.FileName} {_process.StartInfo.Arguments} exited with {exitCode} in {sw.ElapsedMilliseconds} ms.";
+            var message = $"> {FormatProcessInfo(_process.StartInfo)} exited with {exitCode} in {sw.ElapsedMilliseconds} ms.";
             if (exitCode == 0)
             {
                 Reporter.Output.WriteLine(message.Green().Bold());
@@ -206,6 +206,16 @@ namespace Microsoft.DotNet.Cli.Utils
             return this;
         }
 
+        private string FormatProcessInfo(ProcessStartInfo info)
+        {
+            if (string.IsNullOrWhiteSpace(info.Arguments))
+            {
+                return info.FileName;
+            }
+
+            return info.FileName + " " + info.Arguments;
+        }
+
         private void ThrowIfRunning([CallerMemberName] string memberName = null)
         {
             if (_running)

src/Microsoft.DotNet.Cli/Program.cs

@@ -24,8 +24,7 @@ namespace Microsoft.DotNet.Cli
                     return Command.Create("dotnet-" + args[1], "--help")
                         .ForwardStdErr()
                         .ForwardStdOut()
-                        .RunAsync()
+                        .Execute()
-                        .Result
                         .ExitCode;
                 }
                 else
@@ -39,8 +38,7 @@ namespace Microsoft.DotNet.Cli
                 return Command.Create("dotnet-" + args[0], args.Skip(1))
                     .ForwardStdErr()
                     .ForwardStdOut()
-                    .RunAsync()
+                    .Execute()
-                    .Result
                     .ExitCode;
             }
         }

src/Microsoft.DotNet.Tools.Compiler.Csc/Program.cs

@@ -25,8 +25,7 @@ namespace Microsoft.DotNet.Tools.Compiler.Csc
                 var result = RunCsc($"-noconfig @\"{responseFileArg.Value}\"")
                     .ForwardStdErr()
                     .ForwardStdOut()
-                    .RunAsync()
+                    .Execute();
-                    .Result;
 
                 return result.ExitCode;
             });

src/Microsoft.DotNet.Tools.Compiler/Program.cs

@@ -113,8 +113,7 @@ namespace Microsoft.DotNet.Tools.Compiler
                     var compileResult = Command.Create("dotnet-compile", $"--framework {projectDependency.Framework} --configuration {configuration} --no-project-dependencies {projectDependency.Project.ProjectDirectory}")
                             .ForwardStdOut()
                             .ForwardStdErr()
-                            .RunAsync()
+                            .Execute();
-                            .Result;
 
                     if (compileResult.ExitCode != 0)
                     {
@@ -223,9 +222,7 @@ namespace Microsoft.DotNet.Tools.Compiler
                                          Console.Out.WriteLine(line);
                                      }
                                  })
-                                 .RunAsync()
+                                 .Execute();
-                                 .GetAwaiter()
-                                 .GetResult();
 
             foreach (var diag in diagnostics)
             {
@@ -300,9 +297,7 @@ namespace Microsoft.DotNet.Tools.Compiler
                         var result = Command.Create("resgen", $"{fileName} {resourcesFile}")
                                             .ForwardStdErr()
                                             .ForwardStdOut()
-                                            .RunAsync()
+                                            .Execute();
-                                            .GetAwaiter()
-                                            .GetResult();
 
                         if (result.ExitCode != 0)
                         {

src/Microsoft.DotNet.Tools.Publish/Program.cs

@@ -101,8 +101,7 @@ namespace Microsoft.DotNet.Tools.Publish
             var result = Command.Create("dotnet-compile", $"--framework {context.TargetFramework.DotNetFrameworkName} {context.ProjectFile.ProjectDirectory}")
                 .ForwardStdErr()
                 .ForwardStdOut()
-                .RunAsync()
+                .Execute();
-                .Result;
 
             if (result.ExitCode != 0)
             {
@@ -187,9 +186,7 @@ exec ""$DIR/corerun"" ""$DIR/{context.ProjectFile.Name}.exe"" $*
             Command.Create("chmod", $"a+x {outputExe}")
                 .ForwardStdOut()
                 .ForwardStdErr()
-                .RunAsync()
+                .Execute();
-                .GetAwaiter()
-                .GetResult();
 
             return 0;
         }