test_gaussian_blur failure for ppc64le

[gururajrkatti]

I am running the build and test as a part of the Ubuntu distribution for ppc64le.
This helps us simplify testing later when distributions are re-building and re-releasing.

During the build and test, I found that one of the tests is failing.

test_gaussian_blur() is failing for ppc64le. Looks like it is finding that image is not getting changed after the
blur function.

Below is the detailed log

______________________________ test_gaussian_blur ______________________________
fx_asset = local('/home/travis/build/gururajrkatti/wand/tests/assets')
    def test_gaussian_blur(fx_asset):
        with Image(filename=str(fx_asset.join('sasha.jpg'))) as img:
            before = img[100, 100]
            img.gaussian_blur(30, 10)
            after = img[100, 100]
            assert before != after
            assert 0.84 <= after.red <= 0.851
            assert 0.74 <= after.green <= 0.75
            assert 0.655 <= after.blue < 0.67
        with Image(filename='rose:') as img:
            was = img.signature
            img.gaussian_blur(30, 10, channel='red')
>           assert was != img.signature
E           AssertionError: assert 'a698f2fe0c6c31f83d19554a6ec02bac79c961dd9a87e7ed217752e75eb615d7' != 'a698f2fe0c6c31f83d19554a6ec02bac79c961dd9a87e7ed217752e75eb615d7'
E            +  where 'a698f2fe0c6c31f83d19554a6ec02bac79c961dd9a87e7ed217752e75eb615d7' = <wand.image.Image: a698f2f 'PPM' (70x46)>.signature
tests/image_methods_test.py:1033: AssertionError

Note that I have added libmagickwand-dev explicitly as the default setup wasn't having it.
Link to travis build log: https://travis-ci.com/github/gururajrkatti/wand/jobs/444173532

[emcconville]

Hey -- Thanks for posting this! The link to the travis build allows me to recreate the issue, so I should be able to resolve this quickly.