Arch Linux

orlfman

Member

Registered: 2007-11-20

Posts: 144

[SOLVED] I believe the new QT6 in testing breaks KDE on wayland

Updating QT6-packages 6.9.1-1 resulted in a system that cannot load SDDM nor KDE. The only way I was able to get back into my system was boot up a arch iso, chroot in, and disable sddm.service. I then tried to manually boot up arch from the console, but it would just crash. I had to remove SDDM from using wayland to get SDDM to boot back up, and I had to switch to a KDE X11 session to get back into my desktop.

I do not know if its related to using KDE 6.4 Beta 2 or not.

Here is a journald log of the coredump:

Jun 03 09:20:28 linux64 systemd[979]: Started Launch DrKonqi for a systemd-coredump crash (PID 1122/UID 0).
Jun 03 09:20:28 linux64 drkonqi-coredump-launcher[1140]: Unable to find file for pid 1098 expected at "kcrash-metadata/kwin_wayland.5b16cbc982ad4114b3f85f62efc4d932.1098.ini"
Jun 03 09:20:28 linux64 drkonqi-coredump-launcher[1144]: Unable to find file for pid 1113 expected at "kcrash-metadata/kwin_wayland.5b16cbc982ad4114b3f85f62efc4d932.1113.ini"
Jun 03 09:20:28 linux64 kwin_wayland_wrapper[1141]: free(): invalid pointer
Jun 03 09:20:28 linux64 systemd-coredump[1155]: Process 1141 (kwin_wayland) of user 1000 terminated abnormally with signal 6/ABRT, processing...
Jun 03 09:20:28 linux64 systemd[1]: Started Process Core Dump (PID 1155/UID 0).
Jun 03 09:20:28 linux64 systemd[1]: Started Pass systemd-coredump journal entries to relevant user for potential DrKonqi handling.
Jun 03 09:20:28 linux64 systemd-coredump[1156]: [?] Process 1141 (kwin_wayland) of user 1000 dumped core.

                                                Stack trace of thread 1141:
                                                #0  0x00007fde7e4a774c n/a (libc.so.6 + 0x9774c)
                                                #1  0x00007fde7e44ddc0 raise (libc.so.6 + 0x3ddc0)
                                                #2  0x00007fde7e43557a abort (libc.so.6 + 0x2557a)
                                                #3  0x00007fde7e4365c9 n/a (libc.so.6 + 0x265c9)
                                                #4  0x00007fde7e4b1a35 n/a (libc.so.6 + 0xa1a35)
                                                #5  0x00007fde7e4b6ecc __libc_free (libc.so.6 + 0xa6ecc)
                                                #6  0x00007fde7f2fcaed n/a (libQt6Gui.so.6 + 0xfcaed)
                                                #7  0x00007fde7f396b3c _ZN22QGuiApplicationPrivate25createPlatformIntegrationEv (libQt6Gui.so.6 + 0x196b3c)
                                                #8  0x00007fde7f398438 _ZN22QGuiApplicationPrivate21createEventDispatcherEv (libQt6Gui.so.6 + 0x198438)
                                                #9  0x00007fde7eb6c0f5 _ZN23QCoreApplicationPrivate4initEv (libQt6Core.so.6 + 0x16c0f5)
                                                #10 0x00007fde7f3984ce _ZN22QGuiApplicationPrivate4initEv (libQt6Gui.so.6 + 0x1984ce)
                                                #11 0x00007fde7fefa766 _ZN19QApplicationPrivate4initEv (libQt6Widgets.so.6 + 0xfa766)
                                                #12 0x00007fde81888e28 _ZN4KWin11ApplicationC1ERiPPc (libkwin.so.6 + 0x288e28)
                                                #13 0x000055e946183e3c n/a (/usr/bin/kwin_wayland + 0x3ee3c)
                                                #14 0x00007fde7e4376b5 n/a (libc.so.6 + 0x276b5)
                                                #15 0x00007fde7e437769 __libc_start_main (libc.so.6 + 0x27769)
                                                #16 0x000055e94618c385 n/a (/usr/bin/kwin_wayland + 0x47385)

                                                Stack trace of thread 1152:
                                                #0  0x00007fde7e4ade22 n/a (libc.so.6 + 0x9de22)
                                                #1  0x00007fde7e4a1fda n/a (libc.so.6 + 0x91fda)
                                                #2  0x00007fde7e4a2024 n/a (libc.so.6 + 0x92024)
                                                #3  0x00007fde7e51c5a6 ppoll (libc.so.6 + 0x10c5a6)
                                                #4  0x00007fde7d9c7e04 n/a (libglib-2.0.so.0 + 0x5fe04)
                                                #5  0x00007fde7d9c7ee5 g_main_context_iteration (libglib-2.0.so.0 + 0x5fee5)
                                                #6  0x00007fde7ee3c5e2 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x43c5e2)
                                                #7  0x00007fde7eb744b6 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x1744b6)
                                                #8  0x00007fde7ec873c6 _ZN7QThread4execEv (libQt6Core.so.6 + 0x2873c6)
                                                #9  0x00007fde7fc1fdae n/a (libQt6DBus.so.6 + 0x37dae)
                                                #10 0x00007fde7ed1ee69 n/a (libQt6Core.so.6 + 0x31ee69)
                                                #11 0x00007fde7e4a57eb n/a (libc.so.6 + 0x957eb)
                                                #12 0x00007fde7e52918c n/a (libc.so.6 + 0x11918c)
                                                ELF object binary architecture: AMD x86-64
Jun 03 09:20:28 linux64 systemd[1]: systemd-coredump@4-1155-0.service: Deactivated successfully.
Jun 03 09:20:28 linux64 kwin_wayland_wrapper[1163]: free(): invalid pointer
Jun 03 09:20:28 linux64 systemd-coredump[1166]: Process 1163 (kwin_wayland) of user 1000 terminated abnormally with signal 6/ABRT, processing...
Jun 03 09:20:28 linux64 systemd[1]: Started Process Core Dump (PID 1166/UID 0).
Jun 03 09:20:28 linux64 systemd[1]: Started Pass systemd-coredump journal entries to relevant user for potential DrKonqi handling.

Last edited by orlfman (2025-06-04 05:22:58)

BS86

Member

Registered: 2022-11-03

Posts: 71

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

kde-unstable was not yet rebuild after the Qt 6.9.1 update, so that breakage is kinda expected. At least kwin needs a rebuild against Qt 6.9.1.

Last edited by BS86 (2025-06-03 16:39:04)

orlfman

Member

Registered: 2007-11-20

Posts: 144

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

kde-unstable was not yet rebuild after the Qt 6.9.1 update, so that breakage is kinda expected. At least kwin needs a rebuild against Qt 6.9.1.

Ah, that makes sense. I'll stay on X11 until that happens then.

V0VC

Member

Registered: 2024-05-30

Posts: 7

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

Man that was annoying as hell, as if hadn't been busy enough today... Ended up doing this:

 tail -n 200 /var/log/pacman.log | grep -E 'upgraded|installed' | awk '{print $4, $5}' | tr -d '()' | while read pkg version; do echo downgrade --ala-url https://archive.archlinux.org --ignore never --ala-only $pkg -- --nodeps >> dg.sh; done 

k4ever07

Member

Registered: 2024-07-27

Posts: 7

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

I can confirm this. I've been running Plasma 6.4 beta2 for the past few days with no issues. After upgrading today to the qt6 6.9.1 packages, SDDM and the Plasma Wayland session would not run. Also, when switching to the Plasma X11 session, kwin_x11 was not available. After downgrading all 23 qt6 packages from 6.9.1 to 6.9.0, everything is working well again.

BS86

Member

Registered: 2022-11-03

Posts: 71

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

the rebuild was added to kde-unstable 45 minutes ago

k4ever07

Member

Registered: 2024-07-27

Posts: 7

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

the rebuild was added to kde-unstable 45 minutes ago

Thanks for the update! I just updated with the new kwin and qt6 packages, rebooted, and all seems well!

orlfman

Member

Registered: 2007-11-20

Posts: 144

Re: [SOLVED] I believe the new QT6 in testing breaks KDE on wayland

I can confirm as well. The new kwin rebuild for the beta fixed the wayland crashing for both sddm and plasma.