[BUG]: Test test_init_factory_basic fails

Required prerequisites

• Make sure you've read the documentation. Your issue may be addressed there.
• Search the issue tracker and Discussions to verify that this hasn't already been reported. +1 or comment there if it has.
• Consider asking first in the Gitter chat room or in a Discussion.

What version (or hash if on master) of pybind11 are you using?

2.10.3

Problem description

________________________________________________________________________________________ test_init_factory_basic ________________________________________________________________________________________

    def test_init_factory_basic():
        """Tests py::init_factory() wrapper around various ways of returning the object"""
    
        cstats = [
            ConstructorStats.get(c)
            for c in [m.TestFactory1, m.TestFactory2, m.TestFactory3]
        ]
        cstats[0].alive()  # force gc
        n_inst = ConstructorStats.detail_reg_inst()
    
        x1 = m.TestFactory1(tag.unique_ptr, 3)
        assert x1.value == "3"
        y1 = m.TestFactory1(tag.pointer)
        assert y1.value == "(empty)"
        z1 = m.TestFactory1("hi!")
        assert z1.value == "hi!"
    
        assert ConstructorStats.detail_reg_inst() == n_inst + 3
    
        x2 = m.TestFactory2(tag.move)
        assert x2.value == "(empty2)"
        y2 = m.TestFactory2(tag.pointer, 7)
        assert y2.value == "7"
        z2 = m.TestFactory2(tag.unique_ptr, "hi again")
        assert z2.value == "hi again"
    
        assert ConstructorStats.detail_reg_inst() == n_inst + 6
    
        x3 = m.TestFactory3(tag.shared_ptr)
        assert x3.value == "(empty3)"
        y3 = m.TestFactory3(tag.pointer, 42)
        assert y3.value == "42"
        z3 = m.TestFactory3("bye")
        assert z3.value == "bye"
    
        for null_ptr_kind in [tag.null_ptr, tag.null_unique_ptr, tag.null_shared_ptr]:
            with pytest.raises(TypeError) as excinfo:
                m.TestFactory3(null_ptr_kind)
            assert (
                str(excinfo.value) == "pybind11::init(): factory function returned nullptr"
            )
    
        assert [i.alive() for i in cstats] == [3, 3, 3]
        assert ConstructorStats.detail_reg_inst() == n_inst + 9
    
        del x1, y2, y3, z3
        assert [i.alive() for i in cstats] == [2, 2, 1]
        assert ConstructorStats.detail_reg_inst() == n_inst + 5
        del x2, x3, y1, z1, z2
        assert [i.alive() for i in cstats] == [0, 0, 0]
        assert ConstructorStats.detail_reg_inst() == n_inst
    
>       assert [i.values() for i in cstats] == [
            ["3", "hi!"],
            ["7", "hi again"],
            ["42", "bye"],
        ]
E       AssertionError: assert [['33', '3', ...['42', 'bye']] == [['3', 'hi!']...['42', 'bye']]
E         At index 0 diff: ['33', '3', 'hi!'] != ['3', 'hi!']
E         Use -v to get more diff

cstats     = [<pybind11_tests.ConstructorStats object at 0x991925130>, <pybind11_tests.ConstructorStats object at 0x9919252f0>, <pybind11_tests.ConstructorStats object at 0x991925230>]
excinfo    = <ExceptionInfo TypeError('pybind11::init(): factory function returned nullptr') tblen=1>
n_inst     = 57
null_ptr_kind = <pybind11_tests.factory_constructors.tag.null_shared_ptr_tag object at 0x861c10cb0>

../../pybind11-2.10.3/tests/test_factory_constructors.py:62: AssertionError
----------------------------------------------------------------------------------------- Captured stdout call ------------------------------------------------------------------------------------------
### TestFactory1 @ 0x900682480 created 3
### TestFactory1 @ 0x900682460 created via default constructor
### TestFactory1 @ 0x93b6a2d80 created hi!
### TestFactory2 @ 0x93b6a2be0 created via default constructor
### TestFactory2 @ 0x9006824e0 created 7
### TestFactory2 @ 0x8210396d0 created hi again
### TestFactory2 @ 0x900682580 created via move constructor
### TestFactory2 @ 0x8210396d0 destroyed
### TestFactory3 @ 0x900682540 created via default constructor
### TestFactory3 @ 0x900682640 created 42
### TestFactory3 @ 0x900682620 created bye
### TestFactory1 @ 0x900682480 destroyed
### TestFactory2 @ 0x9006824e0 destroyed
### TestFactory3 @ 0x900682640 destroyed
### TestFactory3 @ 0x900682620 destroyed
### TestFactory2 @ 0x93b6a2be0 destroyed
### TestFactory3 @ 0x900682540 destroyed
### TestFactory1 @ 0x900682460 destroyed
### TestFactory1 @ 0x93b6a2d80 destroyed
### TestFactory2 @ 0x900682580 destroyed

Python-3.9
OS: FreeBSD 13.1

Reproducible example code

Test

Is this a regression? Put the last known working version here if it is.

Yes, this is a regression in 2.10.3

Start with tests/test_factory_constructors.py and the test_init_factory_basic failure shown in the report. Reproduce the regression in pybind11 2.10.3 under the reported environment, inspect the related factory-constructor behavior, and consider the work done when the test passes with the expected ConstructorStats values and nullptr errors.