I am able to successfully load the test grib file that was suggested in the README, however when I try to read a grib file such as the one below I get the following error output.

> import cfgrib
> ds = cfgrib.Dataset.frompath('nam.t00z.awip1200.tm00.grib2')
Traceback (most recent call last):
File "<stdin>", line 1, in
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/cfgrib/dataset.py", line 482, in frompath
return cls(stream=messages.Stream(path, mode=mode, message_class=CfMessage), **kwargs)
File "<attrs generated init baa5906ed7dcdc8b722f343b3fe827a76110eccb>", line 7, in init
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/cfgrib/dataset.py", line 485, in attrs_post_init
dims, vars, attrs = build_dataset_components(**self.dict)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/cfgrib/dataset.py", line 457, in build_dataset_components
var_index, encode_parameter, encode_time, encode_geography, encode_vertical,
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/cfgrib/dataset.py", line 372, in build_data_var_components
data_var_attrs = enforce_unique_attributes(index, data_var_attrs_keys)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/cfgrib/dataset.py", line 150, in enforce_unique_attributes
raise ValueError("multiple values for unique attribute %r: %r" % (key, values))
ValueError: multiple values for unique attribute 'typeOfLevel': ['hybrid', 'cloudBase', 'unknown', 'cloudTop']

I've tried with both grib1 and grib2 file types and it seems the formatting is incorrect for all the files I've tried. Any suggestions?