code: function setOptName(opt, optKey) {
      var key$ = optKey + '$';
      opts[key$] = opts[key$] || {};
      var name = opt.name || fspath.basename(opt.path);
      while (opts[key$][name]) {
        name = '_' + name;
      }
      opts[key$][name] = opt;
      opt.name = name;
    }
docs: assign a unique name to opt by indexing opts.[optKey]$ NOTE: this may overwrite opt.name