pypy/module/_pickle/test/apptest_pickle.py::test_recursive_set

def test_recursive_set():
        # Set containing an immutable object containing the original set.
        y = set()
        y.add(K(y))
        for proto in range(4, pickle.HIGHEST_PROTOCOL + 1):
>           s = dumps(y, proto)
E           (application-level) PicklingError: Can't pickle <class 'apptest_pickle.K'>: it's not found as apptest_pickle.K

module/_pickle/test/apptest_pickle.py:440: PicklingError

builder: own-linux-x86-64 build #10880+

test: pypy/module/_pickle/test/apptest_pickle.py::test_recursive_set