TypeError: 'zip' object is not subscriptable

This is the error summary

> -

---> 32 import gin.tf
33 import numpy as np
34 import replay_memory

~/anaconda3/lib/python3.6/site-packages/gin/tf/__init__.py in
66
67 # pylint: disable=unused-import
---> 68 from gin.tf.utils import GinConfigSaverHook
69
70 # pylint: enable=g-import-not-at-top

~/anaconda3/lib/python3.6/site-packages/gin/tf/utils.py in
32
33 # Register TF file reader for Gin's parse_config_file.
---> 34 config.register_file_reader(tf.gfile.Open, tf.gfile.Exists)
35
36

~/anaconda3/lib/python3.6/site-packages/gin/config.py in register_file_reader(*args)
1412 return functools.partial(do_registration, is_readable_fn=args[0])
1413 elif len(args) == 2:
-> 1414 do_registration(*args)
1415 else: # 0 or > 2 arguments supplied.
1416 err_str = 'register_file_reader() takes 1 or 2 arguments ({} given)'

~/anaconda3/lib/python3.6/site-packages/gin/config.py in do_registration(file_reader_fn, is_readable_fn)
1406 """
1407 def do_registration(file_reader_fn, is_readable_fn):
-> 1408 if file_reader_fn not in list(zip(*_FILE_READERS))[0]:
1409 _FILE_READERS.append((file_reader_fn, is_readable_fn))
1410

TypeError: 'zip' object is not subscriptable

1

How do I fix this?