7 tests fail

[yurivict]

=========================================================================================================== FAILURES ===========================================================================================================
_________________________________________________________________________________________________ test_NormalConstraint_pickle _________________________________________________________________________________________________

    def test_NormalConstraint_pickle():
        c = NormalConstraint(("a", "b"), (1, 2), (3, 4))
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.NormalConstraint'>: it's not the same object as iminuit.cost.NormalConstraint

tests/test_cost.py:1100: PicklingError
_______________________________________________________________________________________________ test_ExtendedUnbinnedNLL_pickle ________________________________________________________________________________________________

    def test_ExtendedUnbinnedNLL_pickle():
        c = ExtendedUnbinnedNLL([1, 2], norm_pdf)
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.ExtendedUnbinnedNLL'>: it's not the same object as iminuit.cost.ExtendedUnbinnedNLL

tests/test_cost.py:397: PicklingError
____________________________________________________________________________________________________ test_BinnedNLL_pickle _____________________________________________________________________________________________________

    def test_BinnedNLL_pickle():
        c = BinnedNLL([1], [1, 2], expon_cdf)
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.BinnedNLL'>: it's not the same object as iminuit.cost.BinnedNLL

tests/test_cost.py:608: PicklingError
___________________________________________________________________________________________________ test_LeastSquares_pickle ___________________________________________________________________________________________________

    def test_LeastSquares_pickle():
        c = LeastSquares([1, 2], [2, 3], 0.1, line)
    
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.LeastSquares'>: it's not the same object as iminuit.cost.LeastSquares

tests/test_cost.py:897: PicklingError
________________________________________________________________________________________________ test_ExtendedBinnedNLL_pickle _________________________________________________________________________________________________

    def test_ExtendedBinnedNLL_pickle():
        c = BinnedNLL([1], [1, 2], expon_cdf)
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.BinnedNLL'>: it's not the same object as iminuit.cost.BinnedNLL

tests/test_cost.py:746: PicklingError
_____________________________________________________________________________________________________ test_Template_pickle _____________________________________________________________________________________________________

    def test_Template_pickle():
        n = np.array([1, 2, 3])
        xe = np.array([0, 1, 2, 3])
        t = np.array([[1, 1, 0], [0, 1, 3]])
    
        c = Template(n, xe, t)
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.Template'>: it's not the same object as iminuit.cost.Template

tests/test_cost.py:1345: PicklingError
___________________________________________________________________________________________________ test_UnbinnedNLL_pickle ____________________________________________________________________________________________________

    def test_UnbinnedNLL_pickle():
        c = UnbinnedNLL([1, 2], norm_pdf)
>       b = pickle.dumps(c)
E       _pickle.PicklingError: Can't pickle <class 'iminuit.cost.UnbinnedNLL'>: it's not the same object as iminuit.cost.UnbinnedNLL

tests/test_cost.py:263: PicklingError
=========================================================================================== 7 failed, 598 passed in 73.09s (0:01:13) ===========================================================================================
*** Error code 1

Version: 2.22.0
Python-3.9
FreeBSD 13.2

[HDembinski]

I am at a loss what the problem here could be.