anchor.diff:    // directly. In effect, we don't support truly asynchronous API.
     String code = api.compile(uri, libraryRoot, provider, handler, options).value;
     if (code === null) {
  -    fail('Error: compilation failed.');
  +    fail('Error: Compilation failed.');
     }
     writeString(out, code);
     int jsBytesWritten = code.length;
     info('compiled $dartBytesRead bytes Dart -> $jsBytesWritten bytes JS '
          + 'in ${relativize(cwd, out)}');
  +  if (!explicitOut) {
  +    String input = uriPathToNative(arguments[0]);
  +    String output = relativize(cwd, out);
  +    print('Dart file $input compiled to JavaScript: $output');
  +  }
   }
   
   class AbortLeg {
  
positive.code:       libraryRoot = cwd.resolve(path);
      }),
      new OptionHandler('--out=.*', (String argument) {
        out = cwd.resolve(nativeToUriPath(extractParameter(argument)));
      }),
      new OptionHandler('--allow-mock-compilation', passThrough),
  
negative.code: 
  void helpAndFail(String message) {
    help();
    print('');
    fail(message);
  }
  
  