Bug: attr.exceptions.FrozenInstanceError

[Jasha10]

Hi,

I'm getting an exception whose traceback involves pytest-cases.

Here is a minimal reproducer:

# min_repro_test.py
from pytest import fixture
from pytest_cases import parametrize_with_cases


@fixture
def foo_fixture():
    return 123


class MyCases:
    def case_arr_too_short(self, foo_fixture):
        return 456


@parametrize_with_cases("arg", cases=MyCases)
def test_get_tick_by_tick_sequence_of_best_bids_and_asks(arg) -> None:
    pass

$ pytest min_repro_test.py
================================================================== test session starts ==================================================================
platform linux -- Python 3.10.2, pytest-7.0.0, pluggy-1.0.0
rootdir: /home/jasha10/pysc, configfile: pyproject.toml
plugins: cases-3.6.8
collected 0 items / 1 error

======================================================================== ERRORS =========================================================================
_______________________________________________________ ERROR collecting repro/min_repro_test.py ________________________________________________________
../../miniconda3/envs/repro/lib/python3.10/site-packages/pluggy/_hooks.py:265: in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
../../miniconda3/envs/repro/lib/python3.10/site-packages/pluggy/_manager.py:80: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
../../miniconda3/envs/repro/lib/python3.10/site-packages/_pytest/python.py:257: in pytest_pycollect_makeitem
    res = list(collector._genfunctions(name, obj))
../../miniconda3/envs/repro/lib/python3.10/site-packages/_pytest/python.py:487: in _genfunctions
    fixtures.add_funcarg_pseudo_fixture_def(self, metafunc, fm)
../../miniconda3/envs/repro/lib/python3.10/site-packages/_pytest/fixtures.py:164: in add_funcarg_pseudo_fixture_def
    if not metafunc._calls[0].funcargs:
../../miniconda3/envs/repro/lib/python3.10/site-packages/pytest_cases/plugin.py:931: in __getitem__
    return self.calls_list[item]
../../miniconda3/envs/repro/lib/python3.10/site-packages/pytest_cases/plugin.py:942: in calls_list
    self.create_call_list_from_pending_parametrizations()
../../miniconda3/envs/repro/lib/python3.10/site-packages/pytest_cases/plugin.py:994: in create_call_list_from_pending_parametrizations
    remove_empty_ids(callspec)
../../miniconda3/envs/repro/lib/python3.10/site-packages/pytest_cases/fixture_parametrize_plus.py:556: in remove_empty_ids
    callspec._idlist = [c for c in callspec._idlist if not c.startswith(EMPTY_ID)]
../../miniconda3/envs/repro/lib/python3.10/site-packages/attr/_make.py:642: in _frozen_setattrs
    raise FrozenInstanceError()
E   attr.exceptions.FrozenInstanceError
================================================================ short test summary info ================================================================
ERROR min_repro_test.py - attr.exceptions.FrozenInstanceError
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=================================================================== 1 error in 0.20s ====================================================================

This is with the latest versions if pytest and pytest-cases installed from pypi.org.

[jammer87]

Same issue as #251

[Jasha10]

I see, thanks @jammer87. I will close this issue in favor of #251.