code: function () {
      log();
      log('source', fss.baseRelative(config.source));
      log('target', fss.baseRelative(config.target));
      if (!fss.directoryExists(fss.baseRelative(config.appdir))) {
          log('error', 'no source directory at', config.appdir);
          process.exit(1);
      }
  }
docs: /*
  Initial logging.