Control: retitle -1 gtk4: memorytexture test fails on s390x Control: severity -1 important
I mitigated this in 4.14.4+ds-8 by skipping the memorytexture test during autopkgtest as well as during build-time testing, so I'm downgrading this to important. On Thu, 01 Aug 2024 at 10:15:11 -0400, Jeremy Bícha wrote: > There were several upstream fixes to the memorytexture test in June > and July that aren't in our gtk 4.14.4 > > https://gitlab.gnome.org/GNOME/gtk/-/commits/main/testsuite/gdk/memorytexture.c If you're going to update to 4.15.x in experimental soon *anyway*, then that could be a good opportunity to find out whether the memorytexture test might have been fixed on s390x (again). Sorry, but I have already put more time than I can justify into repeatedly building GTK on porterboxes in the last couple of weeks, so I am probably not going to chase this any time soon. I believe the situation is that it failed in 4.12.x, was fixed in 4.12.x, was fixed differently in 4.13.x, and then regressed in 4.14.x? Or something like that? I'm 95% sure this is because s390x is big-endian and nobody except us is routinely testing (or even building) GTK on big-endian systems. Probably one of the mappings between different libraries' colour channel layouts (GTK, Cairo, OpenGL, Vulkan, ...) is mixing up "first byte is red" with "least significant 8 bits are red", or similar. There have been endianness issues in the past that turned out to be a regression in lower-level libraries like libpixman, so we can't necessarily be sure that this is really a GTK bug. > We do have a patch, > debian/tests-Mark-memorytexture-as-expected-to-fail-on-big-endian.patch > I'm unsure about the significance: did this test actually pass on > s390x in 4.12 and then began failing again in 4.14? Yes. Sebastien Bacher disabled this test in 4.14.4+ds-3 "mark also memorytexture as expected to fail on big endian", without any reference to a Debian or upstream bug; let's use this bug to represent that failure. > gdk/memorytexture.test passes in installed-tests-wayland but not in > installed-tests-x11 That's perhaps interesting input for someone who understands the finer points of OpenGL, but I'm sorry, that's not me. smcv
