semaphore_tracker: There appear to be 1 leaked semaphores to clean up at shutdown len(cache))

Question

I was run an autokeras code via python3.6. There is a warning like this after trained one model:

Saving model.                                                              
+--------------------------------------------------------------------------+
|        Model ID        |          Loss          |      Metric Value      |
+--------------------------------------------------------------------------+
|           0            |    48.8651391018182    |   0.9489116312994325   |
+--------------------------------------------------------------------------+
/usr/local/lib/python3.6/multiprocessing/semaphore_tracker.py:143: UserWarning: semaphore_tracker: There appear to be 1 leaked semaphores to clean up at shutdown
  len(cache))

My training code:

clf = ImageClassifier(verbose=True)
clf.fit(x_train, y_train, time_limit=72*60*60)
clf.final_fit(x_train, y_train, x_test, y_test, retrain=True)
y = clf.evaluate(x_test, y_test)
print(y)

Solution

Seems it is a bug of autokeras.The issue in github is here.