pytest 9.1.0 does not allow overriding fixture's parameters via `@pytest.mark.parametrize(..., indirect=True)` anymore

[rokm]

In pytest 9.1.0, using @pytest.mark.parametrize(..., indirect=True) does not seem to override parameters of a fixture that has parameters explicitly set (i.e., @pytest.fixture(params=[...])) - attempting to do so now results in duplicate parametrization of {fixture_name} error.

This worked with previous releases. git bisect points to d56b1af (and reverting it restores the old behavior).

Minimal example (modeled after pyi_builder fixture from PyInstaller, see here and here):

# test_myfixture.py
import pytest


class MyFixture:
    def __init__(self, mode):
        self.mode = mode

    def do_something(self):
        # Do something depending on self.mode
        pass


@pytest.fixture(params=['first_mode', 'second_mode'])
def myfixture(request):
    yield MyFixture(request.param)


# [1]: typically, both modes are tested
def test_myfixture_default(myfixture):
    assert isinstance(myfixture, MyFixture)
    assert myfixture.mode in {'first_mode', 'second_mode'}
    myfixture.do_something()


# [2]: sometimes, a specific mode is forced
@pytest.mark.parametrize('myfixture', ['first_mode'], indirect=True)
def test_myfixture_single_mode1(myfixture):
    assert isinstance(myfixture, MyFixture)
    assert myfixture.mode == 'first_mode'
    myfixture.do_something()


@pytest.mark.parametrize('myfixture', ['second_mode'], indirect=True)
def test_myfixture_single_mode2(myfixture):
    assert isinstance(myfixture, MyFixture)
    assert myfixture.mode == 'second_mode'
    myfixture.do_something()

Running with 9.0.3:

$ pytest -v -rsfE test_myfixture.py
================================================================================== test session starts ===================================================================================
platform linux -- Python 3.14.5, pytest-9.0.3, pluggy-1.6.0 -- /home/rok/tmp/pyi-pytest/venv/bin/python
cachedir: .pytest_cache
rootdir: /home/rok/tmp/pyi-pytest/myfixture
collected 4 items                                                                                                                                                                        

test_myfixture.py::test_myfixture_default[first_mode] PASSED                                                                                                                       [ 25%]
test_myfixture.py::test_myfixture_default[second_mode] PASSED                                                                                                                      [ 50%]
test_myfixture.py::test_myfixture_single_mode1[first_mode] PASSED                                                                                                                  [ 75%]
test_myfixture.py::test_myfixture_single_mode2[second_mode] PASSED                                                                                                                 [100%]

=================================================================================== 4 passed in 0.01s ====================================================================================

Running with pytest 9.1.0:

$ pytest -v -rsfE test_myfixture.py
================================================================================== test session starts ===================================================================================
platform linux -- Python 3.14.5, pytest-9.1.0, pluggy-1.6.0 -- /home/rok/tmp/pyi-pytest/venv/bin/python
cachedir: .pytest_cache
rootdir: /home/rok/tmp/pyi-pytest/myfixture
collected 0 items / 1 error                                                                                                                                                              

========================================================================================= ERRORS =========================================================================================
___________________________________________________________________________ ERROR collecting test_myfixture.py ___________________________________________________________________________
test_myfixture.py::test_myfixture_single_mode1: duplicate parametrization of 'myfixture'
================================================================================ short test summary info =================================================================================
ERROR test_myfixture.py
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
==================================================================================== 1 error in 0.05s ====================================================================================

Since I cannot seem to find any mention of the behavior change in the changelog, I would like to check if the change is intended or not, before making any changes on our end...

[bluetech]

Thanks for the report and the bisect. Will fix for 9.0.1.