Error while testing for Cifar10 dataset

Here's the error stack trace

Traceback (most recent call last):
  File "Densenet_Cifar10.py", line 270, in <module>
    _, batch_loss, weight_summary = sess.run([train, cost, merged], feed_dict=train_feed_dict)
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 778, in run
    run_metadata_ptr)
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 969, in _run
    fetch_handler = _FetchHandler(self._graph, fetches, feed_dict_string)
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 408, in __init__
    self._fetch_mapper = _FetchMapper.for_fetch(fetches)
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 230, in for_fetch
    return _ListFetchMapper(fetch)
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 337, in __init__
    self._mappers = [_FetchMapper.for_fetch(fetch) for fetch in fetches]
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 337, in <listcomp>
    self._mappers = [_FetchMapper.for_fetch(fetch) for fetch in fetches]
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 227, in for_fetch
    (fetch, type(fetch)))
TypeError: Fetch argument None has invalid type <class 'NoneType'>

tf.summary.merge_all() returns None

taki0112 / Densenet-Tensorflow

Error while testing for Cifar10 dataset #2