Fix accessing PID in TestHostControllersTestHost

src/Platform/Microsoft.Testing.Platform/Hosts/TestHostControllersTestHost.cs

@@ -205,22 +205,25 @@ protected override async Task<int> InternalRunAsync()
             await _logger.LogDebugAsync($"Starting test host process");
             using IProcess testHostProcess = process.Start(processStartInfo);
 
-            testHostProcess.Exited += (sender, e) =>
-            {
-                var processExited = sender as Process;
-                _logger.LogDebug($"Test host process exited, PID: '{processExited?.Id}'");
-            };
-
+            int? testHostProcessId = null;
             try
             {
-                await _logger.LogDebugAsync($"Started test host process '{testHostProcess.Id}' HasExited: {testHostProcess.HasExited}");
+                testHostProcessId = testHostProcess.Id;
             }
             catch (InvalidOperationException) when (testHostProcess.HasExited)
             {
                 // Access PID can throw InvalidOperationException if the process has already exited:
                 // System.InvalidOperationException: No process is associated with this object.
             }
 
+            testHostProcess.Exited += (sender, e) =>
+            {
+                var processExited = sender as Process;
+                _logger.LogDebug($"Test host process exited, PID: '{testHostProcessId}'");
+            };
+
+            await _logger.LogDebugAsync($"Started test host process '{testHostProcessId}' HasExited: {testHostProcess.HasExited}");
+
             string? seconds = configuration[PlatformConfigurationConstants.PlatformTestHostControllersManagerSingleConnectionNamedPipeServerWaitConnectionTimeoutSeconds];
             int timeoutSeconds = seconds is null ? TimeoutHelper.DefaultHangTimeoutSeconds : int.Parse(seconds, CultureInfo.InvariantCulture);
             await _logger.LogDebugAsync($"Setting PlatformTestHostControllersManagerSingleConnectionNamedPipeServerWaitConnectionTimeoutSeconds '{timeoutSeconds}'");