fields() from DataClasses not working properly

Hey I just wanted to ask about strange error I have. fileds() from dataclasses not working properly if dataclass is declared outside running function.

Minimalistic example:

DataClass in function

from dataclasses import dataclass, fields

import submitit


def run():
    @dataclass
    class Test:
        test: str = "test"
        u: int = 1

    t = Test()
    print(f"Test: {fields(t)}")
    return 1


executor = submitit.AutoExecutor(folder="log_test")
executor.update_parameters(timeout_min=1, slurm_partition="dev")
job = executor.submit(run)
print(job.result())
print(job.stdout())

Print:

Test: (Field(name='test',type=<class 'str'>,default='test',default_factory=<dataclasses._MISSING_TYPE object at 0x7f5bceda6cd0>,init=True,repr=True,hash=None,compare=True,metadata=mappingproxy({}),_field_type=_FIELD), Field(name='u',type=<class 'int'>,default=1,default_factory=<dataclasses._MISSING_TYPE object at 0x7f5bceda6cd0>,init=True,repr=True,hash=None,compare=True,metadata=mappingproxy({}),_field_type=_FIELD))

DataClass outside function

from dataclasses import dataclass, fields

import submitit

@dataclass
class Test:
    test: str = "test"
    u: int = 1

def run():
    t = Test()
    print(f"Test: {fields(t)}")
    return 1


executor = submitit.AutoExecutor(folder="log_test")
executor.update_parameters(timeout_min=1, slurm_partition="dev")
job = executor.submit(run)
print(job.result())
print(job.stdout())

Print:

Test: ()

The exact same thing happens on slurm cluster with python 3.7.4 and on my local computer without slurm with python 3.9. Is this submitit or threading issue?

[jgbos]

Looks like we are all hitting this issue at the same time: https://github.com/facebookresearch/hydra/issues/1621

[gwenzek]

I think it should work if you move the dataclass to another file and that you import it.