Nedelec 2nd kind H(curl) fails on 32-bit systems

[drew-parsons]

Judging by the build errors at https://buildd.debian.org/status/package.php?p=basix, looks like Nedelec 2nd kind H(curl) is not compatible with 32 bit systems. e.g.
i386 https://buildd.debian.org/status/fetch.php?pkg=basix&arch=i386&ver=0.0.1%7Egit20210122.4f10ef2-1&stamp=1612391676&raw=0
armel https://buildd.debian.org/status/fetch.php?pkg=basix&arch=armel&ver=0.0.1%7Egit20210122.4f10ef2-1&stamp=1612398463&raw=0
armhf https://buildd.debian.org/status/fetch.php?pkg=basix&arch=armhf&ver=0.0.1%7Egit20210122.4f10ef2-1&stamp=1612392128&raw=0

Is this problem expected? Is it something that can be fixed, or should Nedelec 2nd kind H(curl) just be considered not supported on 32 bit systems?

The error message is

__ test_permutation_of_tabulated_data_tetrahedron[5-Nedelec 2nd kind H(curl)] __

element_name = 'Nedelec 2nd kind H(curl)', order = 5

    @pytest.mark.parametrize("element_name", tetrahedron_elements)
    @pytest.mark.parametrize("order", range(1, 6))
    def test_permutation_of_tabulated_data_tetrahedron(element_name, order):
        if element_name == "Crouzeix-Raviart" and order != 1:
            pytest.xfail()
    
        e = basix.create_element(element_name, "tetrahedron", order)
    
        N = 4
        points = np.array([[i / N, j / N, k / N]
                           for i in range(N + 1) for j in range(N + 1 - i) for k in range(N + 1 - i - j)])
        values = e.tabulate(0, points)[0]
    
        start = sum(e.entity_dofs[0])
        ndofs = e.entity_dofs[1][0]
        if ndofs != 0:
            # Check that the 0th permutation undoes the effect of reflecting edge 0
            reflected_points = np.array([[p[0], p[2], p[1]] for p in points])
            reflected_values = e.tabulate(0, reflected_points)[0]
    
            if e.mapping_name == "affine":
                pass
            elif e.mapping_name == "covariant piola":
                for i, r in enumerate(reflected_values):
                    for j in range(e.dim):
                        reflected_values[i][j + e.dim::e.dim] = r[j + e.dim::e.dim][::-1]
            elif e.mapping_name == "contravariant piola":
                for i, r in enumerate(reflected_values):
                    for j in range(e.dim):
                        reflected_values[i][j] = -r[j]
                        reflected_values[i][j + e.dim::e.dim] = -r[j + e.dim::e.dim][::-1]
            elif e.mapping_name == "double covariant piola":
                pytest.skip()  # TODO: implement double covariant piola
            else:
                raise ValueError(f"Unknown mapping: {e.mapping_name}")
    
            for i, j in zip(values, reflected_values):
                for d in range(e.value_size):
                    i_slice = i[d * e.dim:(d + 1) * e.dim]
                    j_slice = j[d * e.dim:(d + 1) * e.dim]
>                   assert np.allclose((e.base_permutations[0].dot(i_slice))[start: start + ndofs],
                                       j_slice[start: start + ndofs])
E                   assert False
E                    +  where False = <function allclose at 0xf6d2a658>(array([ 0., -0., -0., -0., -0.,  0.]), array([-1.34, -1.12, -0.28,  0.68,  0.8 , -1.5 ]))
E                    +    where <function allclose at 0xf6d2a658> = np.allclose

test/test_permutations.py:227: AssertionError

In the meantime since only this one test fails, I'll just skip this test in the 32-bit Debian builds. So the error won't show in future builds (but will still be there).

[drew-parsons]

Might be worth noting, in principle orders 1 to 6 should have been tested, but only order 5 is triggering this error.

[mscroggs]

Is this still an issue?