Tensorboard callback with keras fit_generator, 'Function' has no attribute 'fetch_callbacks' - python-2.7

Question

I am trying to run a model using keras's fit_generator with a tensorboard_callback for profiling a specific epoch. I am running the following code for the generator:
def gen(source):
loopable = iter(source)
for batch in loopable:
yield (batch[0], batch[1])
In the main training script I am instantiating the generator and using the model with a tensorboard callback as follows:
train_gen = gen(train_datasource)
log_dir="logs/profile/" + datetime.datetime.now().strftime("%Y%m%d-%H%M%S")
tensorboard_callback = tf.keras.callbacks.TensorBoard(log_dir=log_dir, histogram_freq=1, profile_batch = 3)
m.fit_generator(train_gen, epochs=5, steps_per_epoch=500, use_multiprocessing=True, workers=32, callbacks=[tensorboard_callback])
The main issue I am facing is that the training always halts with the error 'Function' has no attribute 'fetch_callbacks' with the following stack trace:
m.fit_generator(train_gen, epochs=5, steps_per_epoch=500, use_multiprocessing=True, workers=32, callbacks=[tensorboard_callback])
File "/usr/local/lib/python2.7/dist-packages/keras/legacy/interfaces.py", line 91, in wrapper
return func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/keras/engine/training.py", line 1418, in fit_generator
initial_epoch=initial_epoch)
File "/usr/local/lib/python2.7/dist-packages/keras/engine/training_generator.py", line 177, in fit_generator
callbacks.on_epoch_begin(epoch)
File "/usr/local/lib/python2.7/dist-packages/keras/callbacks.py", line 65, in on_epoch_begin
callback.on_epoch_begin(epoch, logs)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/keras/callbacks_v1.py", line 386, in on_epoch_begin
self.merged] = self._fetch_callback
AttributeError: 'Function' object has no attribute 'fetch_callbacks'
I am using tensorflow 1.15 also tried downgrading to 1.14 but still no success. I am trying to train with the tensorboard callback to debug the performance for a specific epoch other than the first one. But so far my attempts have failed to make the callback function correctly. I made sure the GPU is running and detected correctly too.
Any help would be much appreciated.

Answer 1

I ended up using tf.keras fit function instead of fit generator and it worked correctly as expected:
m.fit(x=train_gen, epochs=5, steps_per_epoch=500, use_multiprocessing=True, workers=8, callbacks=[tensorboard_callback])