anchor.diff:      if (_validators == null) {
         _validators = <DoctorValidator>[];
         _validators.add(new _FlutterValidator());
  +      _validators.add(new _HostExecutableValidator());
   
         if (_androidWorkflow.appliesToHostPlatform)
           _validators.add(_androidWorkflow);
  
positive.code: 
  import 'android/android_studio_validator.dart';
  import 'android/android_workflow.dart';
  import 'base/common.dart';
  import 'base/context.dart';
  import 'base/file_system.dart';
  
negative.code: 
      return new ValidationResult(valid, messages,
        statusInfo: 'on ${osName()}, channel ${version.channel}');
    }
  }
  
  class _HostExecutableValidator extends DoctorValidator {
    _HostExecutableValidator() : super('Host Executable Compatibility');
  
    bool _genSnapshotRuns(String genSnapshotPath) {
      final int kExpectedExitCode = 255;
      try {
        return processManager.runSync(<String>[genSnapshotPath]).exitCode == kExpectedExitCode;
      } catch (error) {
        return false;
      }
    }
  
    @override
    Future<ValidationResult> validate() async {
      final String genSnapshotPath =
        artifacts.getArtifactPath(Artifact.genSnapshot);
      final List<ValidationMessage> messages = <ValidationMessage>[];
      final bool hostExecutablesRun = _genSnapshotRuns(genSnapshotPath);
      final ValidationType valid = hostExecutablesRun ? ValidationType.installed : ValidationType.missing;
  
      if (hostExecutablesRun) {
        messages.add(new ValidationMessage('Downloaded executables execute on host'));
      } else {
        messages.add(new ValidationMessage.error(
          'Downloaded executables cannot execute on host. See https://github.com/flutter/flutter/issues/6207 for more information'));
      }
      return new ValidationResult(valid, messages);
    }
  }
  
  