Runtime error from "minimal start" script

Hello,

I’m attempting to run the minimal start example on https://simpletransformers.ai/docs/multi-class-classification/, modified to be CPU-only:

# Create a ClassificationModel
model = ClassificationModel( "bert", "bert-base-cased", num_labels=3, args=model_args, use_cuda=False )

I installed simple transformers as described here https://simpletransformers.ai/docs/installation/, opting for the CPU-only installation (which means I did not install “Apex”).

Running this, I get thousands of the following section logged to console. It does not exit, but I have haad it running for ~half an hour now and it just keeps on emitting the following errors:

INFO:simpletransformers.classification.classification_model: Converting to features started. Cache is not used.
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 125, in _main
    prepare(preparation_data)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 236, in prepare
    _fixup_main_from_path(data['init_main_from_path'])
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 287, in _fixup_main_from_path
    main_content = runpy.run_path(main_path,
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/runpy.py", line 263, in run_path
    return _run_module_code(code, init_globals, run_name,
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/runpy.py", line 96, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/Users/jkearl/Desktop/test.py", line 39, in <module>
    model.train_model(train_df)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/site-packages/simpletransformers/classification/classification_model.py", line 258, in train_model
    train_dataset = self.load_and_cache_examples(train_examples, verbose=verbose)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/site-packages/simpletransformers/classification/classification_model.py", line 803, in load_and_cache_examples
    features = convert_examples_to_features(
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/site-packages/simpletransformers/classification/classification_utils.py", line 364, in convert_examples_to_features
    with Pool(process_count) as p:
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/context.py", line 119, in Pool
    return Pool(processes, initializer, initargs, maxtasksperchild,
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/pool.py", line 212, in __init__
    self._repopulate_pool()
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/pool.py", line 303, in _repopulate_pool
    return self._repopulate_pool_static(self._ctx, self.Process,
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/pool.py", line 326, in _repopulate_pool_static
    w.start()
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/process.py", line 121, in start
    self._popen = self._Popen(self)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/context.py", line 283, in _Popen
    return Popen(process_obj)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/popen_spawn_posix.py", line 32, in __init__
    super().__init__(process_obj)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/popen_fork.py", line 19, in __init__
    self._launch(process_obj)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/popen_spawn_posix.py", line 42, in _launch
    prep_data = spawn.get_preparation_data(process_obj._name)
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 154, in get_preparation_data
    _check_not_importing_main()
  File "/Users/jkearl/anaconda3/envs/transformers/lib/python3.8/multiprocessing/spawn.py", line 134, in _check_not_importing_main
    raise RuntimeError('''
RuntimeError: 
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.

I’m on macOS Moajve, running with latest anaconda.

[JacksonKearl]

conda install python=3.7
pip install simpletransformers

fixed it, thanks.

[OnePunchMann]

check model_args.py u need to set dataloader_num_workers: int = 0