Bug#1057782: gtk4: FTBFS on big-endian: memorytexture test fails

[Simon McVittie]

Source: gtk4
Version: 4.12.4+ds-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)
X-Debbugs-Cc: debian-s390 at lists.debian.org

>From https://buildd.debian.org/status/fetch.php?pkg=gtk4&arch=s390x&ver=4.12.4%2Bds-1&stamp=1701103591&raw=0
> test:         gtk:gdk / memorytexture
> start time:   16:40:53
> duration:     0.64s
> result:       killed by signal 6 SIGABRT
> ...
> 1..2072
> # Start of memorytexture tests
> # Start of download_1x1 tests
> # Start of b8g8r8a8-premultiplied tests
> ok 1 /memorytexture/download_1x1/b8g8r8a8-premultiplied/local
> not ok /memorytexture/download_1x1/b8g8r8a8-premultiplied/gl - ERROR:../../../testsuite/gdk/memorytexture.c:819:compare_textures: 'gdk_memory_format_pixel_equal (format, accurate_compare, data1 + bpp * x, data2 + bpp * x)' should be TRUE

The same test fails on ppc64, which makes me think this is an endianness
bug, probably introduced in the new upstream release 4.12.4. I'm looking
into it.

cc debian-s390 since it is our only big-endian release architecture.

    smcv