diff --git a/gulpfile.js b/gulpfile.js
index c633e1e79..0c55baef8 100755
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -198,7 +198,7 @@ const browserify_plugin = (pluginName, watch = true) => {
   .on('log', (info) => watch && !production && gutil.log(GREEN__ + '[' + pluginName + ']' + __RESET + ' →', info));
 
   // remove source map file
-  del([`${src}/plugin.js.map`]);
+  del([`${src}/plugin.js.map`], {force: true});
 
   const rebundle = () => {
     const version = get_version(pluginName);
diff --git a/src/components/Catalog.vue b/src/components/Catalog.vue
index 192ac6b06..6fba75df2 100644
--- a/src/components/Catalog.vue
+++ b/src/components/Catalog.vue
@@ -388,7 +388,7 @@ export default {
           _layers.push(layer);
         }
         if (null !== layer.nodes && undefined !== layer.nodes) {
-          _layers = _layers.concat(this._traverseVisibleLayers(layer.nodes, _layers));
+          this._traverseVisibleLayers(layer.nodes, _layers);
         }
       }
       return _layers;