local variable 'logs' referenced before assignmenについて

前提・実現したいこと

リンク内容
こちらのプログラムを元にCNNを用いたペットボトルの画像認識をしたいのですが、モデルを学習させる段階が上手くいきません。

発生している問題・エラーメッセージ

---------------------------------------------------------------------------
UnboundLocalError                         Traceback (most recent call last)
<ipython-input-23-cbf32f617328> in <module>
      5                   epochs=10,
      6                   batch_size=6,
----> 7                   validation_data=(X_test,y_test))

c:\users\sern3\appdata\local\programs\python\python36\lib\site-packages\tensorflow\python\keras\engine\training.py in _method_wrapper(self, *args, **kwargs)
    106   def _method_wrapper(self, *args, **kwargs):
    107     if not self._in_multi_worker_mode():  # pylint: disable=protected-access
--> 108       return method(self, *args, **kwargs)
    109 
    110     # Running inside `run_distribute_coordinator` already.

c:\users\sern3\appdata\local\programs\python\python36\lib\site-packages\tensorflow\python\keras\engine\training.py in fit(self, x, y, batch_size, epochs, verbose, callbacks, validation_split, validation_data, shuffle, class_weight, sample_weight, initial_epoch, steps_per_epoch, validation_steps, validation_batch_size, validation_freq, max_queue_size, workers, use_multiprocessing)
   1102               end_step = step + data_handler.step_increment
   1103               callbacks.on_train_batch_end(end_step, logs)
-> 1104         epoch_logs = copy.copy(logs)
   1105 
   1106         # Run validation.

UnboundLocalError: local variable 'logs' referenced before assignmen

該当のソースコード

python
1model = model.fit(X_train,
2                  y_train,
3                  epochs=10,
4                  batch_size=6,
5                  validation_data=(X_test,y_test))