Respond to feedback and add missing file

src/Compilers/Extension/CompilerExtension.csproj

@@ -102,6 +102,7 @@
       <IncludeOutputGroupsInVSIX>BuiltProjectOutputGroup</IncludeOutputGroupsInVSIX>
       <IncludeOutputGroupsInVSIXLocalOnly>DebugSymbolsProjectOutputGroup%3b</IncludeOutputGroupsInVSIXLocalOnly>
       <ForceIncludeInVSIX>true</ForceIncludeInVSIX>
+      <!-- Workaround for https://github.com/dotnet/sdk/issues/433#issuecomment-320024771 . Remove once resolved. -->
       <AdditionalProperties>TargetFramework=net46</AdditionalProperties>
     </ProjectReference>
     <ProjectReference Include="..\CSharp\csc\csc.csproj">

src/Compilers/Server/VBCSCompiler/CoreClrCompilerServerHost.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+#if NETCOREAPP2_0
+
+using System;
+using System.Collections.Immutable;
+
+namespace Microsoft.CodeAnalysis.CompilerServer
+{
+    internal sealed class CoreClrCompilerServerHost : CompilerServerHost
+    {
+        private static readonly IAnalyzerAssemblyLoader s_analyzerLoader = new CoreClrAnalyzerAssemblyLoader();
+
+        // Caches are used by C# and VB compilers, and shared here.
+        public static readonly Func<string, MetadataReferenceProperties, PortableExecutableReference> SharedAssemblyReferenceProvider = (path, properties) => new CachingMetadataReference(path, properties);
+
+        public override IAnalyzerAssemblyLoader AnalyzerAssemblyLoader => s_analyzerLoader;
+
+        public override Func<string, MetadataReferenceProperties, PortableExecutableReference> AssemblyReferenceProvider => SharedAssemblyReferenceProvider;
+
+        internal CoreClrCompilerServerHost(string clientDirectory, string sdkDirectory)
+            : base(clientDirectory, sdkDirectory)
+        {
+        }
+
+        public override bool CheckAnalyzers(string baseDirectory, ImmutableArray<CommandLineAnalyzerReference> analyzers)
+        {
+            return AnalyzerConsistencyChecker.Check(baseDirectory, analyzers, s_analyzerLoader);
+        }
+    }
+}
+
+#endif

src/Compilers/Server/VBCSCompiler/DesktopBuildServerController.cs

@@ -39,6 +39,8 @@ protected override IClientConnectionHost CreateClientConnectionHost(string pipeN
         }
 
         protected internal override TimeSpan? GetKeepAliveTimeout()
+        {
+            try
             {
                 int keepAliveValue;
                 string keepAliveStr = _appSettings[KeepAliveSettingName];
@@ -60,6 +62,12 @@ protected override IClientConnectionHost CreateClientConnectionHost(string pipeN
                     return ServerDispatcher.DefaultServerKeepAlive;
                 }
             }
+            catch (Exception e)
+            {
+                CompilerServerLogger.LogException(e, "Could not read AppSettings");
+                return ServerDispatcher.DefaultServerKeepAlive;
+            }
+        }
 
         protected override Task<Stream> ConnectForShutdownAsync(string pipeName, int timeout)
         {