jsonnet not loading even though installed

Running macOS Big Sur (11.2.3). I installed allennlp successfully with pip in my sys environment. The installed version is jsonnet-0.17.0. When I try to run the train script, I get this warning and then error:

WARNING - allennlp.common.params - _jsonnet not loaded, treating sequential_sentence_classification/config.jsonnet as json
Traceback (most recent call last):
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/****/sequential_sentence_classification/src/allennlp/allennlp/run.py", line 21, in
run()
File "/****/sequential_sentence_classification/src/allennlp/allennlp/run.py", line 18, in run
main(prog="allennlp")
File "/****/sequential_sentence_classification/src/allennlp/allennlp/commands/__init__.py", line 102, in main
args.func(args)
File "/****/sequential_sentence_classification/src/allennlp/allennlp/commands/train.py", line 124, in train_model_from_args
args.cache_prefix)
File "/****/sequential_sentence_classification/src/allennlp/allennlp/commands/train.py", line 162, in train_model_from_file
params = Params.from_file(parameter_filename, overrides)
File "/****/sequential_sentence_classification/src/allennlp/allennlp/common/params.py", line 477, in from_file
file_dict = json.loads(evaluate_file(params_file, ext_vars=ext_vars))
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/__init__.py", line 348, in loads
return _default_decoder.decode(s)
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)