res_file.py

import decorator

def failme(func):
    def wrapped(func, *args, **kwargs):
        raise Exception()
    return decorator.decorator(wrapped, func)

test_decorator.py

import pytest
from resources import resources

resources.register_mod("res_file")
from res_file import failme


@failme
@pytest.fixture(scope='class')
def fail_fixture():
    pass


def test_failing_fixture(fail_fixture):
   assert True


if __name__ == "__main__":
    pytest.main()