Unable to train RawNet1 using Keras

[ac-alpha]

I am facing this error which trying to run the 01-trn_RawNet.py script.

Traceback (most recent call last):
  File "01-trn_RawNet.py", line 279, in <module>
    loss, loss1, loss2, acc1, acc2 = model.train_on_batch([x, y], [dummy_y, dummy_y])
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/keras/engine/training.py", line 918, in train_on_batch
    outputs = self.train_function(ins)  # pylint: disable=not-callable
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/keras/backend.py", line 3510, in __call__
    outputs = self._graph_fn(*converted_inputs)
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/eager/function.py", line 572, in __call__
    return self._call_flat(args)
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/eager/function.py", line 671, in _call_flat
    outputs = self._inference_function.call(ctx, args)
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/eager/function.py", line 445, in call
    ctx=ctx)
  File "/root/.local/lib/python3.6/site-packages/tensorflow/python/eager/execute.py", line 67, in quick_execute
    six.raise_from(core._status_to_exception(e.code, message), None)
  File "<string>", line 3, in raise_from
tensorflow.python.framework.errors_impl.InvalidArgumentError:  Cannot update variable with shape [] using a Tensor with shape [4], shapes must be equal.
         [[node metrics/s_bs_loss_accuracy/AssignAddVariableOp (defined at 01-trn_RawNet.py:279) ]] [Op:__inference_keras_scratch_graph_16089]

Function call stack:
keras_scratch_graph

Can you please help me out? I am using tensorflow 2.0.0-beta1. I am using a batch size of 4.

[ac-alpha]

I changed metrics=["accuracy"] to metrics=[] while compiling the model and removed acc1 and acc2 from the line leading to error as these variables are not being used.