KeyError: 'product' when ducling handling keyword 'meat' about python-duckling HOT 5 CLOSED

Python 3.6.4 | packaged by conda-forge | (default, Dec 23 2017, 16:54:01)
[GCC 4.2.1 Compatible Apple LLVM 6.1.0 (clang-602.0.53)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import duckling
>>> d = DucklingWrapper()
# duration works fine:
>>> d.parse('5 days')
[{'dim': 'number', 'text': '5', 'start': 0, 'end': 1, 'value': {'value': 5.0}}, {'dim': 'duration', 'text': '5 days', 'start': 0, 'end': 6, 'value': {'value': 5.0, 'unit': 'day', 'year': None, 'month': None, 'day': 5, 'hour': None, 'minute': None, 'second': None}}, {'dim': 'distance', 'text': '5', 'start': 0, 'end': 1, 'value': {'value': 5.0, 'unit': None}}, {'dim': 'volume', 'text': '5', 'start': 0, 'end': 1, 'value': {'value': 5.0, 'unit': None, 'latent': True}}, {'dim': 'temperature', 'text': '5', 'start': 0, 'end': 1, 'value': {'value': 5.0, 'unit': None}}, {'dim': 'time', 'text': '5', 'start': 0, 'end': 1, 'value': {'value': '2018-04-10T05:00:00.000-04:00', 'grain': 'hour', 'others': [{'grain': 'hour', 'value': '2018-04-10T05:00:00.000-04:00'}, {'grain': 'hour', 'value': '2018-04-10T17:00:00.000-04:00'}, {'grain': 'hour', 'value': '2018-04-11T05:00:00.000-04:00'}]}}]
# this does not:
>>> d.parse('5 cups of sugar')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/hilary/anaconda3/lib/python3.6/site-packages/duckling/wrapper.py", line 237, in parse
    return self._parse(input_str, reference_time=reference_time)
  File "/Users/hilary/anaconda3/lib/python3.6/site-packages/duckling/wrapper.py", line 56, in _parse
    reference_time=reference_time)
  File "/Users/hilary/anaconda3/lib/python3.6/site-packages/duckling/duckling.py", line 161, in parse
    return self._parse_result(duckling_result)
  File "/Users/hilary/anaconda3/lib/python3.6/site-packages/duckling/duckling.py", line 187, in _parse_result
    field.getValue(), entry[u'dim'])
  File "/Users/hilary/anaconda3/lib/python3.6/site-packages/duckling/duckling.py", line 222, in _parse_dict
    result[key] = _functions[key](field.getValue())
KeyError: 'product'

{
  "project": "detector",
  "language": "en",
  "pipeline": ["nlp_spacy", "tokenizer_spacy", "intent_entity_featurizer_regex", "intent_featurizer_spacy", "ner_crf",
               "ner_duckling", "ner_spacy", "ner_synonyms", "intent_classifier_sklearn"],
  "path" : "models/",
  "data" : "data/train.json",
  "response_log": "logs/",
  "duckling_dimensions": ["duration", "time"],
  "intent_classifier_sklearn": {
    "C": [1, 2, 5, 10, 20, 100],
    "kernel": "linear"
  }
}

  File ".../lib/python3.6/site-packages/duckling/duckling.py", line 222, in _parse_dict
    result[key] = _functions[key](field.getValue())
KeyError: 'product'