Bug#1026445: mutter: test failure on armhf and sometimes armel: ../../src/xcb_io.c:626: _XAllocID: Assertion `ret != inval_id' failed

[Simon McVittie]

Control: severity -1 important

On Tue, 20 Dec 2022 at 11:47:10 +0000, Simon McVittie wrote:
> Recent uploads of mutter have had a FTBFS on armhf and sometimes armel,
> with this test failure in "mutter:core+mutter/wayland / xwayland"

In 43.2-4 I've downgraded failures in this test to be non-fatal,
reducing the severity of this issue.

> The same test failure has not been seen on arm64 or on non-ARM
> architectures, for whatever reason (in particular, other slower
> architectures like riscv64 and mips*el don't seem to have this
> problem).

This is probably because d/rules in mutter explicitly skips the
tests on riscv64 and mips*el. I'd prefer to re-enable the tests on
all architectures (even if all failures are ignored on some of them)
now that it's using Meson, in which all tests have a finite timeout,
but that will probably need to happen via experimental in order to avoid
disrupting migration.

One important and possibly relevant difference between 32-bit ARM and
arm64 is that on 32-bit ARM, we explicitly set the default driver in
mutter's fork of cogl to be OpenGL|ES 2 instead of OpenGL 3, using
non-upstreamed patches. I'd like to be able to stop applying those
patches, but that will need input from users of proprietary GPU drivers
on ARM.

    smcv