code: function (path, currentFileInfo, callback) {
              var parserImporter = this;
              this.queue.push(path);
  
              //
              // Import a file asynchronously
              //
              less.Parser.importer(path, currentFileInfo, function (e, root, fullPath) {
                  parserImporter.queue.splice(parserImporter.queue.indexOf(path), 1); // Remove the path from the queue
  
                  var imported = fullPath in parserImporter.files;
  
                  parserImporter.files[fullPath] = root;                        // Store the root
  
                  if (e && !parserImporter.error) { parserImporter.error = e; }
                  
                  callback(e, root, imported);
              }, env);
          }
docs: Error in parsing/evaluating an import