anchor.diff:    // Stop at 'debugger' statement.
     hasStoppedAtBreakpoint,
     (Isolate mainIsolate) async {
  -    for (var i = 0; i < Platform.script.pathSegments.length; i++) {
  -      print('segment $i: "${Platform.script.pathSegments[i]}"');
  -    }
  -    print('Directory: $directory');
       // Grab the VM.
       VM vm = mainIsolate.vm;
       await vm.reloadIsolates();
  
positive.code: 
      // Reload to v3.
      response = await slaveIsolate.reloadSources(
        rootLibUri: '$directory${Platform.pathSeparator}'
                    'complex_reload${Platform.pathSeparator}'
                    'v3${Platform.pathSeparator}'
                    'main.dart',
      );
      expect(response['success'], isTrue);
  
  
negative.code: import 'dart:io';
  import 'service_test_common.dart';
  import 'package:observatory/service.dart';
  import 'package:path/path.dart' as path;
  import 'package:unittest/unittest.dart';
  
  // Chop off the file name.
  String baseDirectory =
      path.dirname(Platform.script.path) + Platform.pathSeparator;
  
  Uri baseUri = Platform.script.replace(path: baseDirectory);
  Uri spawnUri = baseUri.resolveUri(Uri.parse('complex_reload/v1/main.dart'));
  Uri v2Uri = baseUri.resolveUri(Uri.parse('complex_reload/v2/main.dart'));
  Uri v3Uri = baseUri.resolveUri(Uri.parse('complex_reload/v3/main.dart'));
  
  testMain() async {
    print(baseUri);
    debugger();  // Stop here.
    // Spawn the child isolate.
    I.Isolate isolate =
        await I.Isolate.spawnUri(spawnUri,
                                 [],
                                 null);
    print(isolate);
    debugger();
  }
  
  Future<String> invokeTest(Isolate isolate) async {
    await isolate.reload();
  