anchor.diff:        'A compile() invocation is still executing.';
   
     /// Options used by the kernel compiler.
  -  final ProcessedOptions _options;
  +  final CompilerOptions _compilerOptions;
   
     /// The logger to report compilation progress.
     final PerformanceLog _logger;
  
positive.code:       ..fileSystem = new _FileSystemAdaptor(fsState, pathContext)
        ..byteStore = byteStore
        ..onError = errorListener.onError;
      var processedOptions = new ProcessedOptions(options);
  
      return new FrontEndCompiler._(
          processedOptions, uriTranslator, errorListener);
    }
  
    FrontEndCompiler._(this._options, this.uriTranslator, this._errorListener)
        : _logger = _options.logger,
          _fileSystem = _options.fileSystem;
  
    /// Compile the library with the given absolute [uri], and everything it
    /// depends on. Return the result of the requested library compilation.
  
negative.code:       }
      }
  
      return _runWithFrontEndContext('Compile', uri, (processedOptions) async {
        try {
          // Initialize the dill target once.
          if (_dillTarget == null) {
            _dillTarget = new DillTarget(
              processedOptions.ticker,
              uriTranslator,
              processedOptions.target,
            );
          }
  
          // Append new libraries from the current component.
  