title: Failed copying input tensor from CPU to GPU in order to run GatherVe: Dst tensor is not initialized. [Op:GatherV2]
body: <pre><code>    from random import sample
      index=sample(range(0, len(result)), len(result)//5*4)
      description_train=[child[0] for i, child in enumerate(result) if i in index]
      ipc_train=[child[1] for i, child in enumerate(result) if i in index]
      description_test=[child[0] for i, child in enumerate(result) if i not in index]
      ipc_test=[child[1] for i, child in enumerate(result) if i not in index]
      
      import numpy as np
      
      def to_onehot(li):
          result=np.zeros(8)
          if 'A' in li:
              result[0]=1
          if 'B' in li:
              result[1]=1
          if 'C' in li:
              result[2]=1
          if 'D' in li:
              result[3]=1
          if 'E' in li:
              result[4]=1
          if 'F' in li:
              result[5]=1
          if 'G' in li:
              result[6]=1
          if 'H' in li:
              result[7]=1
          return result
              
              
      
      from tensorflow.python.keras.preprocessing.text import Tokenizer
      
      
      max_words=100000
      num_classes=8
      
      t=Tokenizer(num_words=max_words)
      t.fit_on_texts(description_train)
      X_train=t.texts_to_matrix(description_train, mode='binary')
      X_test=t.texts_to_matrix(description_test, mode='binary')
      Y_train=np.array([to_onehot(child) for child in ipc_train], dtype=np.int32)
      Y_test=np.array([to_onehot(child) for child in ipc_test], dtype=np.int32)
      
      
      from tensorflow.python.keras.models import Sequential
      from tensorflow.python.keras.layers import Dense, Dropout
      
      
      model = Sequential()
      model.add(Dense(1024, input_shape=(max_words,), activation='relu'))
      model.add(Dense(128, activation='relu'))
      model.add(Dense(num_classes, activation='sigmoid'))
      
      model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])
      model.fit(X_train, Y_train, batch_size=128, epochs=5, validation_split=0.1)
  </code></pre>
  <p>the last line (model.fit) result in a following error.</p>
  <pre><code>InternalError: Failed copying input tensor from /job:localhost/replica:0/task:0/device:CPU:0 to /job:localhost/replica:0/task:0/device:GPU:0 in order to run GatherV2: Dst tensor is not initialized. [Op:GatherV2]
  </code></pre>
  <p>How can I fix it?
  thank you in advance.</p>