$ pytest tests/test_more.py 
========================================================= test session starts =========================================================
platform linux -- Python 3.14.0, pytest-8.4.2, pluggy-1.6.0
rootdir: /tmp/unification
configfile: pyproject.toml
collected 8 items                                                                                                                     

tests/test_more.py .F.F....                                                                                                     [100%]

============================================================== FAILURES ===============================================================
____________________________________________________ test_unify_nonstandard_object ____________________________________________________

    def test_unify_nonstandard_object():
        _unify.add((ast.AST, ast.AST, Mapping), _unify_object)
        x = var()
>       assert unify(ast.Num(n=1), ast.Num(n=1), {}) == {}
                     ^^^^^^^
E       AttributeError: module 'ast' has no attribute 'Num'

tests/test_more.py:36: AttributeError
____________________________________________________ test_reify_nonstandard_object ____________________________________________________

    def test_reify_nonstandard_object():
        _reify.add((ast.AST, Mapping), _reify_object)
        x = var()
>       assert reify(ast.Num(n=1), {}).n == 1
                     ^^^^^^^
E       AttributeError: module 'ast' has no attribute 'Num'

tests/test_more.py:54: AttributeError
======================================================= short test summary info =======================================================
FAILED tests/test_more.py::test_unify_nonstandard_object - AttributeError: module 'ast' has no attribute 'Num'
FAILED tests/test_more.py::test_reify_nonstandard_object - AttributeError: module 'ast' has no attribute 'Num'
===================================================== 2 failed, 6 passed in 0.07s =====================================================