test_binary_diff() fails

I am running tests at my machine and test_binary_diff() fails with following error:

repo = pygit2.Repository('/tmp/pytest/test_binary_diff0/binaryfilerepo/.git/')

    def test_binary_diff(repo):
        diff = repo.diff('HEAD', 'HEAD^')
        assert PATCH_BINARY == diff.patch
        diff = repo.diff('HEAD', 'HEAD^', flags=DiffOption.SHOW_BINARY)
>       assert PATCH_BINARY_SHOW == diff.patch
E       AssertionError: assert 'diff --git a...vrst3ey5{\n\n' == 'diff --git a...vrst3ey5{\n\n'
E         Skipping 154 identical leading characters in diff, use -v to show
E           teral 8
E         - PcwS>j%FIhFs^kIy3n&7R
E         ?   ^^^^
E         + Pc${NM%FIhFs^kIy3n&7R
E         ?   ^^^^
E           ...

Start by running test_binary_diff() and compare the generated SHOW_BINARY diff with PATCH_BINARY_SHOW, focusing on the differing binary content shown in the assertion. Trace the repository diff call and its binary-output behavior; the work is done when the test produces the expected stable patch output.