anchor.diff:        config = mixologist.parseConfig(yaml.loadYaml(configString));
       })
       .then((_) =>
  -        mixologist.mix(config, new LocalFileSystem(new io.Directory('./lib'))))
  +        mixologist.mix(config, new LocalFileSystem(searchDir)))
       .then((String code) {
         var outputFilePath = path.join(outputDir.path, config.output);
         new io.Directory(path.dirname(outputFilePath)).createSync(recursive: true);
  
positive.code:       help: 'Output directory',
        callback: (value) {
          outputDir = new io.Directory(value);
        });
    argp.parse(args);
    if (outputDir == null || configFile == null) {
  
negative.code: 
  io.Directory outputDir;
  io.File configFile;
  io.Directory searchDir;
  
  main(List<String> args) {
    parseArgs(args);
  