Splits invalid when collection order not deterministic

The big assumption underlying the two splitting algorithms is that the order of collected items is constant.
However, I've come across a case where this assumption was violated.
In my case I had a test parametrised with pytest.mark.parametrize, but the items to parametrize with would sometimes change order.

Take this example:

import pytest

@pytest.mark.parametrize('name', set(['henk', 'ingrid']))
def test_hello(name):
    pass

If you run this often enough you'll see that the order changes:

[2021-06-17 22:47:10] test_temp.py::test_hello[henk] PASSED                                                                                                                [ 50%]
[2021-06-17 22:47:10] test_temp.py::test_hello[ingrid] PASSED                                                                                                              [100%]

and

[2021-06-17 22:47:10] test_temp.py::test_hello[ingrid] PASSED                                                                                                              [ 50%]
[2021-06-17 22:47:10] test_temp.py::test_hello[henk] PASSED                                                                                                                [100%]

I'm not sure how to address this, but I think there are a few options:

1. not splitting over different values of parametrize for the same test. In other words, make sure that a single group will run all tests for test_hello.
2. try to create some deterministic order out of test cases by sorting. I'm not sure this will work in all cases tho (for example it might not work for objects)
3. do splitting on one machine, save the splits and just call pytest with those pre-calculated groups (so not really using this plugin as a plugin :p)

Reproduisez la variation de l’ordre avec l’exemple pytest.mark.parametrize, puis suivez les deux algorithmes de division ; aucun chemin de fichier ni aucun test n’est fourni. Comparez les stratégies de gestion proposées et considérez l’issue comme résolue lorsque des exécutions répétées affectent les tests collectés à des groupes cohérents sans interrompre la collecte de pytest.