diff --git a/build-tools/xaprepare/xaprepare/Steps/Step_DetermineAzurePipelinesTestJobs.cs b/build-tools/xaprepare/xaprepare/Steps/Step_DetermineAzurePipelinesTestJobs.cs
index 1c6ba1b97ce..006165c9c0d 100644
--- a/build-tools/xaprepare/xaprepare/Steps/Step_DetermineAzurePipelinesTestJobs.cs
+++ b/build-tools/xaprepare/xaprepare/Steps/Step_DetermineAzurePipelinesTestJobs.cs
@@ -16,27 +16,32 @@ protected override async Task<bool> Execute (Context context)
 		{
 			Log.StatusLine ("Determining test jobs to run...");
 
+			var runAllTestsLoggingCommand = "##vso[task.setvariable variable=TestAreas;isOutput=true]MSBuild,MSBuildDevice,BCL,Designer";
+
 			string commitRevision = Environment.GetEnvironmentVariable ("BUILD_SOURCEVERSION");
 			string commitMessage = Environment.GetEnvironmentVariable ("BUILD_SOURCEVERSIONMESSAGE");
 			if (string.IsNullOrEmpty (commitRevision) || string.IsNullOrEmpty (commitMessage)) {
-				Log.ErrorLine ("One or more source version variable values were empty:");
-				Log.ErrorLine ($"BUILD_SOURCEVERSION='{commitRevision}' BUILD_SOURCEVERSIONMESSAGE='{commitMessage}'.");
-				return false;
+				Log.WarningLine ("One or more source version variable values were empty:");
+				Log.WarningLine ($"BUILD_SOURCEVERSION='{commitRevision}' BUILD_SOURCEVERSIONMESSAGE='{commitMessage}'.");
+				Log.MessageLine (runAllTestsLoggingCommand);
+				return true;
 			}
 
-			// Assume we're building a merge commit as part of an Azure Pipelines PR build. Otherwise, this step will fail.
+			// Assume we're building a merge commit as part of an Azure Pipelines PR build. Otherwise, run all tests.
 			//  Example: Merge 0b66502c8b9f33cbb8d21b2dab7c100629aec081 into 0bef8aa5cd74d83d77c4e2b3f63975a0deb804b3
 			var commitMessagePieces = commitMessage.Split (new string [] { " " }, StringSplitOptions.RemoveEmptyEntries);
 			if (string.IsNullOrEmpty (commitMessagePieces [3])) {
-				Log.ErrorLine ($"Unable to parse merge commit message from: '{commitMessage}'.");
-				return false;
+				Log.WarningLine ($"Unable to parse merge commit message from: '{commitMessage}'.");
+				Log.MessageLine (runAllTestsLoggingCommand);
+				return true;
 			}
 
 			var git = new GitRunner (context);
 			var filesChanged = await git.RunCommandForOutputAsync (BuildPaths.XamarinAndroidSourceRoot, "diff", "--name-only", commitRevision, commitMessagePieces [3]);
 			if (filesChanged == null || filesChanged.Count < 1) {
-				Log.ErrorLine ($"Unable to determine if any files were changed in this PR.");
-				return false;
+				Log.WarningLine ($"Unable to determine if any files were changed in this PR.");
+				Log.MessageLine (runAllTestsLoggingCommand);
+				return true;
 			}
 
 			var testAreas = new HashSet<string> ();