test_RGB fails on ppc64le with python 3.7

[step21]

Description

ppc64le python 3.7
test_RGB

Way to reproduce

run tests on ppc64le with python 3.7 (conda based)

Version information

[hmaarrfk]

___________________________________ test_RGB ___________________________________

    def test_RGB():
        img = gaussian(data.text(), 1)
        imgR = np.zeros((img.shape[0], img.shape[1], 3))
        imgG = np.zeros((img.shape[0], img.shape[1], 3))
        imgRGB = np.zeros((img.shape[0], img.shape[1], 3))
        imgR[:, :, 0] = img
        imgG[:, :, 1] = img
        imgRGB[:, :, :] = img[:, :, None]
        r = np.linspace(136, 50, 100)
        c = np.linspace(5, 424, 100)
        init = np.array([r, c]).T
        snake = active_contour(imgR, init, boundary_condition='fixed',
                               alpha=0.1, beta=1.0, w_line=-5, w_edge=0, gamma=0.1,
                               coordinates='rc')
        refr = [136, 135, 134, 133, 132, 131, 129, 128, 127, 125]
        refc = [5, 9, 13, 17, 21, 25, 30, 34, 38, 42]
        assert_equal(np.array(snake[:10, 0], dtype=np.int32), refr)
        assert_equal(np.array(snake[:10, 1], dtype=np.int32), refc)
        snake = active_contour(imgG, init, boundary_condition='fixed',
                               alpha=0.1, beta=1.0, w_line=-5, w_edge=0, gamma=0.1,
                               coordinates='rc')
>       assert_equal(np.array(snake[:10, 0], dtype=np.int32), refr)
E       AssertionError: 
E       Arrays are not equal
E       
E       Mismatched elements: 9 / 10 (90%)
E       Max absolute difference: 686
E       Max relative difference: 5.488
E        x: array([ 136,   57,  -21,  -99, -177, -255, -332, -409, -485, -561],
E             dtype=int32)
E        y: array([136, 135, 134, 133, 132, 131, 129, 128, 127, 125])
../_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_pla/lib/python3.7/site-packages/skimage/segmentation/tests/test_active_contour_model.py:76: AssertionError

https://travis-ci.com/github/conda-forge/scikit-image-feedstock/jobs/345385697
conda-forge/scikit-image-feedstock#61