Make tye exit if dotnet fails to start projects (#588)

src/Microsoft.Tye.Hosting/ProcessRunner.cs

@@ -149,8 +149,7 @@ namespace Microsoft.Tye.Hosting
 
                 if (buildResult.ExitCode != 0)
                 {
-                    _logger.LogInformation("Building projects failed with exit code {ExitCode}: \r\n" + buildResult.StandardOutput, buildResult.ExitCode);
-                    return;
+                    throw new TyeBuildException($"Building projects failed with exit code {buildResult.ExitCode}: \r\n{buildResult.StandardOutput}");
                 }
             }
 

src/Microsoft.Tye.Hosting/TyeBuildException.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.Serialization;
+
+namespace Microsoft.Tye.Hosting
+{
+    [Serializable]
+    internal class TyeBuildException : Exception
+    {
+        public TyeBuildException()
+        {
+        }
+
+        public TyeBuildException(string? message) : base(message)
+        {
+        }
+
+        public TyeBuildException(string? message, Exception? innerException) : base(message, innerException)
+        {
+        }
+
+        protected TyeBuildException(SerializationInfo info, StreamingContext context) : base(info, context)
+        {
+        }
+    }
+}

src/Microsoft.Tye.Hosting/TyeHost.cs

@@ -91,7 +91,15 @@ namespace Microsoft.Tye.Hosting
 
             _logger.LogInformation("Dashboard running on {Address}", app.Addresses.First());
 
-            await _processor.StartAsync(_application);
+            try
+            {
+                await _processor.StartAsync(_application);
+            }
+            catch (TyeBuildException ex)
+            {
+                _logger.LogError(ex.Message);
+                _lifetime.StopApplication();
+            }
 
             if (_options.Dashboard)
             {