pytest skip marker for when a test must not be run under pytest-xdist -n setting since it does something that requires say all gpus untouched

require_no_pytest_distributed.py

# this goes into transformers/testing_utils.py

_pytest_num_workers = 1

def set_pytest_num_workers(n):
    """
    This is helper method that sets how many pytest workers are used (if under pytest-xdist's -n option)
    """
    _pytest_num_workers = n

def require_no_pytest_distributed(test_case):
    """
    Decorator marking a test that requires that the test suite isn't running under pytest-xdist with more than one worker (i.e. no `pytest -n 2` or higher).
    """
    if _pytest_num_workers > 1:
        return unittest.skip("test must not be run under pytest-xdist where n > 1")(test_case)
    else:
        return test_case

# this goes into tests/conftest.py

def pytest_configure(config):
    # some tests need to know whether they are being run alone or in parallel with pytest-xdist multiple workers
    from transformers.testing_utils import set_pytest_num_workers

    pytest_num_workers = config.getoption("-n")
    print(f"GOT {pytest_num_workers} procs")
    if pytest_num_workers is not None:
        set_pytest_num_workers(pytest_num_workers)
        
# this goes into the test after importing it

@require_no_pytest_distributed
def test_something(): ...