`TestBinaryErosionAndDilation` is flaky

https://jenkins.preferred.jp/job/chainer/job/cupy_pr/2163/#showFailuresLink

tests.cupyx_tests.scipy_tests.ndimage_tests.test_morphology.BinaryErosionAndDilation_param_123_{border_value=0, connectivity=1, density=0.1, filter='binary_dilation', iterations=0, origin=0, output=None, shape=(16, 15), x_dtype=float32}.test_binary_erosion_and_dilation
--
tests.cupyx_tests.scipy_tests.ndimage_tests.test_morphology.BinaryErosionAndDilation_param_269_{border_value=0, connectivity=1, density=0.5, filter='binary_dilation', iterations=0, origin=0, output=None, shape=(5, 7, 9), x_dtype=float32}.test_binary_erosion_and_dilation
--

[toslunar]

No ndimage_tests failure in the last shuffle test 🎉

[grlee77]

I did see this on a couple of other PRs and it was a different parameterized case each time. I haven’t been able to reproduce it locally. It does seem like it has always been the cupy-py3 configuration that failed, though.

This was the case that came up once in the binary morphology PR:

tests.cupyx_tests.scipy_tests.ndimage_tests.test_morphology.BinaryErosionAndDilation_param_279_{border_value=0, connectivity=1, density=0.5, filter='binary_dilation', iterations=0, origin=-1, output=None, shape=(16, 15), x_dtype=float32}.test_binary_erosion_and_dilation