Add more resiliency when communicating with DTE

Since this is a cross-process operation that may involve attempting to acquire the UI thread while the target VS is actually busy, it may actually fail with a COM exception. In that case, default to not throwing, since that destabilizes the MSBuild process and causes us to not recover the active tracking once the UI thread lock is gone.

Author: kzu

src/SmallSharp.Build/MonitorActiveDocument.cs

@@ -21,19 +21,26 @@ public override bool Execute()
             if (LaunchProfiles == null || UserFile == null || FlagFile == null)
                 return true;
 
-            if (BuildEngine4.GetRegisteredTaskObject(nameof(ActiveDocumentMonitor), RegisteredTaskObjectLifetime.AppDomain) is not ActiveDocumentMonitor monitor)
+            try
             {
-                if (WindowsInterop.GetServiceProvider() is IServiceProvider services)
+                if (BuildEngine4.GetRegisteredTaskObject(nameof(ActiveDocumentMonitor), RegisteredTaskObjectLifetime.AppDomain) is not ActiveDocumentMonitor monitor)
                 {
-                    BuildEngine4.RegisterTaskObject(nameof(ActiveDocumentMonitor),
-                        new ActiveDocumentMonitor(LaunchProfiles, UserFile, FlagFile, services),
-                        RegisteredTaskObjectLifetime.AppDomain, false);
+                    if (WindowsInterop.GetServiceProvider() is IServiceProvider services)
+                    {
+                        BuildEngine4.RegisterTaskObject(nameof(ActiveDocumentMonitor),
+                            new ActiveDocumentMonitor(LaunchProfiles, UserFile, FlagFile, services),
+                            RegisteredTaskObjectLifetime.AppDomain, false);
+                    }
+                }
+                else
+                {
+                    // NOTE: this means we only support ONE project/launchProfiles per IDE.
+                    monitor.Refresh(LaunchProfiles, UserFile, FlagFile);
                 }
             }
-            else
+            catch (Exception e)
             {
-                // NOTE: this means we only support ONE project/launchProfiles per IDE.
-                monitor.Refresh(LaunchProfiles, UserFile, FlagFile);
+                Log.LogWarning($"Failed to start active document monitoring: {e}");
             }
 
             return true;

src/SmallSharp.Build/WindowsInterop.cs

@@ -29,7 +29,7 @@ public static void EnsureOpened(string filePath, TimeSpan delay = default)
 
                 dte.ExecuteCommand("File.OpenFile", filePath);
             }
-            catch 
+            catch
             {
                 Debug.Fail($"Failed to open {filePath}.");
             }
@@ -43,11 +43,20 @@ public static void EnsureOpened(string filePath, TimeSpan delay = default)
             if (delay != default)
                 Thread.Sleep(delay);
 
-            var dte = GetDTE();
-            if (dte == null)
-                return null;
+            try
+            {
 
-            return new OleServiceProvider(dte);
+                var dte = GetDTE();
+                if (dte == null)
+                    return null;
+
+                return new OleServiceProvider(dte);
+            }
+            catch
+            {
+                Debug.Fail("Failed to get IDE service provider.");
+                return null;
+            }
         }
 
         static EnvDTE.DTE? GetDTE()