anchor.diff:  
     String toString() => "_CompilationCrash(${errorString})";
   }
  +
  +Future<T> runWithPrintToStderr<T>(Future<T> f()) {
  +  return runZoned(() => new Future<T>(f),
  +      zoneSpecification: new ZoneSpecification(
  +          print: (_1, _2, _3, String line) => stderr.writeln(line)));
  +}
  
positive.code:       : super(fileSystem, platformKernel, strongMode: strongMode);
  
    @override
    Future<Program> compile(Uri script) async {
      if (generator == null) {
        generator = await IncrementalKernelGenerator.newInstance(options, script);
      }
  
negative.code: ///
  library runtime.tools.kernel_service;
  
  import 'dart:async' show Future, ZoneSpecification, runZoned;
  import 'dart:io' show Platform, stderr hide FileSystemEntity;
  import 'dart:isolate';
  import 'dart:typed_data' show Uint8List;
  
  