anchor.diff:      exitCode = 1;
       return;
     }
  -
  +  // Print information about the resolved builders to compare with.
     for (final builder in configurations.builders) {
       if (localConfiguration != null) {
         print("Testing the named configuration $localConfiguration "
  
positive.code:           "compared with builder $builder");
      }
    }
  
    // Use given commit or find out where the current HEAD branched.
    final commit = options["commit"] ??
        await findMergeBase(options["remote"], options["branch"]);
    print("Base commit is $commit");
  
    // Store the downloaded results and our test results in a temporary directory.
    final outDirectory = await Directory.systemTemp.createTemp("test.dart.");
    try {
      final mergedResults = <String, Map<String, dynamic>>{};
      final mergedFlaky = <String, Map<String, dynamic>>{};
  
      bool needsConfigurationOverride = localConfiguration != null &&
          localConfiguration != namedConfigurations.single;
      bool needsMerge = configurations.builders.length > 1;
  
      // Use the buildbucket API to search for builds of the right commit.
      final inexactBuilds = <String, String>{};
      for (final builder in configurations.builders) {
        // Download the previous results and flakiness info from cloud storage.
        print("Finding build on builder $builder to compare with...");
        final buildSearchResult =
            await searchForApproximateBuild(builder, commit);
        if (buildSearchResult.commit != commit) {
  
negative.code:       }
        final buildNumber = buildSearchResult.build.toString();
        print("Downloading results from builder $builder build $buildNumber...");
        tasks.add(cpGsutil(
            buildFileCloudPath(builder, buildNumber, "results.json"),
            "${outDirectory.path}/$previousFileName"));
        if (!options["report-flakes"]) {
          tasks.add(cpGsutil(
              buildFileCloudPath(builder, buildNumber, "flaky.json"),
              "${outDirectory.path}/$flakyFileName"));
        }
      }
      // Run the tests.
      final configurationsToRun = localConfiguration != null
          ? <String>[localConfiguration]
          : namedConfigurations;
      print("".padLeft(80, "="));
      print("Running tests");
      print("".padLeft(80, "="));
  