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

[Simon McVittie]

Source: mutter
Version: 43.2-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)
X-Debbugs-Cc: libx11 at packages.debian.org, debian-arm at lists.debian.org
User: debian-arm at lists.debian.org
Usertags: armel armhf

Recent uploads of mutter have had a FTBFS on armhf and sometimes armel,
with this test failure in "mutter:core+mutter/wayland / xwayland":

> Starting D-Bus daemons (session & system)...
> Launching required services...
> Starting mocked services...
> Running test case...
> # random seed: R02Sbd5b457b9c18c15b967e5a1eb0e1b2ed
> # libmutter-MESSAGE: Running Mutter Test (using mutter 43.2) as a Wayland display server
> libmutter-Message: 22:46:22.853: Running Mutter Test (using mutter 43.2) as a Wayland display server
> # GLib-GIO-DEBUG: _g_io_module_get_default: Found default implementation memory (GMemorySettingsBackend) for ‘gsettings-backend’
> # libmutter-MESSAGE: Created surfaceless renderer without GPU
> libmutter-Message: 22:46:23.040: Created surfaceless renderer without GPU
> # GLib-GIO-DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
> # libmutter-MESSAGE: Disabling DMA buffer screen sharing (not hardware accelerated)
> libmutter-Message: 22:46:23.127: Disabling DMA buffer screen sharing (not hardware accelerated)
> # libmutter-MESSAGE: Disabling DMA buffer screen sharing (implicit modifiers not supported)
> libmutter-Message: 22:46:23.127: Disabling DMA buffer screen sharing (implicit modifiers not supported)
> # libmutter-DEBUG: WL: loaded libnvidia-egl-wayland.so.1:wl_eglstream_controller.
> # libmutter-MESSAGE: Using public X11 display :512, (using :513 for managed services)
> libmutter-Message: 22:46:23.129: Using public X11 display :512, (using :513 for managed services)
> # libmutter-MESSAGE: Using Wayland display name 'mutter-test-display'
> libmutter-Message: 22:46:23.129: Using Wayland display name 'mutter-test-display'
> Window manager warning: Failed to set environment variable GNOME_SETUP_DISPLAY for gnome-session: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name "org.gnome.SessionManager" does not exist
> Window manager warning: Failed to set environment variable DISPLAY for gnome-session: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name "org.gnome.SessionManager" does not exist
> Window manager warning: Failed to set environment variable XAUTHORITY for gnome-session: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name "org.gnome.SessionManager" does not exist
> Window manager warning: Failed to set environment variable WAYLAND_DISPLAY for gnome-session: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name "org.gnome.SessionManager" does not exist
> 1..2
> # Start of backends tests
> # Start of xwayland tests
> # Start of restart tests
> # libmutter-INFO: Acquired name org.gnome.Mutter.InputMapping
> # libmutter-INFO: Acquired name org.gnome.Mutter.ScreenCast
> # libmutter-INFO: Acquired name org.gnome.Mutter.RemoteDesktop
> (WW) Option "-listen" for file descriptors is deprecated
> Please use "-listenfd" instead.
> (WW) Option "-listen" for file descriptors is deprecated
> Please use "-listenfd" instead.
> Failed to initialize glamor, falling back to sw
> # GLib-DEBUG: unsetenv() is not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> # GLib-DEBUG: unsetenv() is not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> # libmutter-MESSAGE: Using public X11 display :512, (using :513 for managed services)
> libmutter-Message: 22:46:23.782: Using public X11 display :512, (using :513 for managed services)
> ok 1 /backends/xwayland/restart/selection
> # End of restart tests
> # Start of crash tests
> # libmutter-test-DEBUG: Test client process (null) exited with exit status 1
> (WW) Option "-listen" for file descriptors is deprecated
> Please use "-listenfd" instead.
> (WW) Option "-listen" for file descriptors is deprecated
> Please use "-listenfd" instead.
> Failed to initialize glamor, falling back to sw
> # GLib-DEBUG: unsetenv() is not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> # GLib-DEBUG: setenv()/putenv() are not thread-safe and should not be used after threads are created
> mutter-xwayland: ../../src/xcb_io.c:626: _XAllocID: Assertion `ret != inval_id' failed.

This appears to be an assertion failure in libX11 rather than in mutter
itself, so it might be a bug in libX11 rather than in mutter, or perhaps
mutter is using it wrong.

This seems to happen consistently on armhf. On armel, retrying the build
of 43.2-1 was successful, but then 43.2-3 failed with the same symptom.

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). Is there anything known to be different about armel and armhf
specifically?

    smcv