Under qt6-qtwayland 6.9.1-2, when a locked KDE Plasma session attempts to display the lockscreen GUI so that the user can unlock the session, the normal GUI cannot be displayed. Instead the user sees a message directing them to drop to a TTY and unlock the session. (See the screenshot from another user at: https://bugs.kde.org/attachment.cgi?id=182760.) Reverting to qt6-qtwayland 6.9.1-1 (and changing no other packages) resolved the issue for me. On my system, potentially relevant journal entries are: Jun 28 19:15:40 fedora-myhostname kscreenlocker_greet[4308]: qml: The backend got an unknown wallpaper provider type. The wallpaper will now fall back to the default. Please check your wallpaper configuration! Jun 28 19:15:40 fedora-myhostname PackageKit[2399]: get-updates transaction /58_bddbbdcd from uid 1000 finished with success after 3359ms Jun 28 19:15:40 fedora-myhostname kscreenlocker_greet[4308]: file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/lockscreen/LockOsd.qml:10:1: "../osd": no such directory Jun 28 19:15:40 fedora-myhostname audit[4308]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=4308 comm="kscreenlocker_g" exe="/usr/libexec/kscreenlocker_greet" sig=11 res=1 Jun 28 19:15:40 fedora-myhostname kernel: kscreenlocker_g[4308]: segfault at 550 ip 00007f203c96e19d sp 00007fff3670f270 error 4 in libLayerShellQtInterface.so.6.4.1[319d,7f203c96b000+7000] likely on CPU 5 (core 1, socket 0) Jun 28 19:15:40 fedora-myhostname kernel: Code: be 02 00 00 00 4c 89 e7 31 c0 e8 2e da ff ff 49 83 7e 10 00 0f 85 8b 00 00 00 49 8b 87 b0 01 00 00 48 85 c0 74 32 4c 8b 63 18 <4c> 8b 70 18 44 8b 6d a8 4c 89 e7 e8 53 d9 ff ff 48 83 ec 08 31 d2 Jun 28 19:15:41 fedora-myhostname kscreenlocker_greet[4358]: qml: The backend got an unknown wallpaper provider type. The wallpaper will now fall back to the default. Please check your wallpaper configuration! Jun 28 19:15:41 fedora-myhostname kscreenlocker_greet[4358]: file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/lockscreen/LockOsd.qml:10:1: "../osd": no such directory Jun 28 19:15:41 fedora-myhostname kernel: kscreenlocker_g[4358]: segfault at 560 ip 00007f2740c9719d sp 00007ffca29c6a10 error 4 in libLayerShellQtInterface.so.6.4.1[319d,7f2740c94000+7000] likely on CPU 4 (core 0, socket 0) Jun 28 19:15:41 fedora-myhostname kernel: Code: be 02 00 00 00 4c 89 e7 31 c0 e8 2e da ff ff 49 83 7e 10 00 0f 85 8b 00 00 00 49 8b 87 b0 01 00 00 48 85 c0 74 32 4c 8b 63 18 <4c> 8b 70 18 44 8b 6d a8 4c 89 e7 e8 53 d9 ff ff 48 83 ec 08 31 d2 Jun 28 19:15:41 fedora-myhostname audit[4358]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=4358 comm="kscreenlocker_g" exe="/usr/libexec/kscreenlocker_greet" sig=11 res=1 Reproducible: Always Steps to Reproduce: 1. Be running KDE Plasma with version 6.9.1-2 of qt6-qtwayland 2. Lock the session 3. Attempt to unlock (by pressing a key or moving the mouse) Actual Results: Plasma displays a screen with a message "The screen locker is broken and unlocking is not possible anymore. In order to unlock it, switch to a virtual terminal..." [followed by instructions for how to unlock from TTY]. Expected Results: Plasma lockscreen should appear, allowing the user to enter a password and unlock the session
I suspect the log lines with '"../osd": no such directory' aren't relevant here, since I see those under 6.9.1-1 too - including on a system which has never had 6.9.1-2 and has never had this lockscreen issue.
I have had even more severe problems after updating to qt6-qtwayland-0:6.9.1-2. Almost every application crashes on startup (including the crash reporter, and frequently the plasma shell itself). I cannot downgrade either: > sudo dnf downgrade qt6-qtwayland > Updating and loading repositories: > Repositories loaded. > Failed to resolve the transaction: > Problem: problem with installed package > - installed package plasma-discover-kns-6.4.1-1.fc42.x86_64 requires libQt6Core.so.6(Qt_6.9)(64bit), but none of the providers can be installed > - package plasma-discover-kns-6.4.1-1.fc42.x86_64 from updates requires libQt6Core.so.6(Qt_6.9)(64bit), but none of the providers can be installed > - cannot install both qt6-qtbase-6.8.2-3.fc42.x86_64 from fedora and qt6-qtbase-6.9.1-1.fc42.x86_64 from @System > - cannot install both qt6-qtbase-6.8.2-3.fc42.x86_64 from fedora and qt6-qtbase-6.9.1-1.fc42.x86_64 from updates > - package qt6-qtwayland-6.8.2-1.fc42.x86_64 from fedora requires qt6-qtbase(x86-64) = 6.8.2, but none of the providers can be installed > - package qt6-qtwayland-6.8.2-1.fc42.x86_64 from fedora requires libQt6Core.so.6(Qt_6.8_PRIVATE_API)(64bit), but none of the providers can be installed > - conflicting requests > You can try to add to command line: > --skip-broken to skip uninstallable packages I'm not brave enough to try the --skip-broken option. I had to install plasma-workspace-x11 and use the X11 session to get a functional System back. The following are some related reports: https://retrace.fedoraproject.org/faf/reports/1245634/ https://retrace.fedoraproject.org/faf/reports/1245856/ Thank you for your time :)
(In reply to Thomas Hepp from comment #2) > I have had even more severe problems after updating to > qt6-qtwayland-0:6.9.1-2. > Almost every application crashes on startup (including the crash reporter, > and frequently the plasma shell itself). > > I cannot downgrade either: > > sudo dnf downgrade qt6-qtwayland > > Updating and loading repositories: > > Repositories loaded. > > Failed to resolve the transaction: > > Problem: problem with installed package > > - installed package plasma-discover-kns-6.4.1-1.fc42.x86_64 requires libQt6Core.so.6(Qt_6.9)(64bit), but none of the providers can be installed > > - package plasma-discover-kns-6.4.1-1.fc42.x86_64 from updates requires libQt6Core.so.6(Qt_6.9)(64bit), but none of the providers can be installed > > - cannot install both qt6-qtbase-6.8.2-3.fc42.x86_64 from fedora and qt6-qtbase-6.9.1-1.fc42.x86_64 from @System > > - cannot install both qt6-qtbase-6.8.2-3.fc42.x86_64 from fedora and qt6-qtbase-6.9.1-1.fc42.x86_64 from updates > > - package qt6-qtwayland-6.8.2-1.fc42.x86_64 from fedora requires qt6-qtbase(x86-64) = 6.8.2, but none of the providers can be installed > > - package qt6-qtwayland-6.8.2-1.fc42.x86_64 from fedora requires libQt6Core.so.6(Qt_6.8_PRIVATE_API)(64bit), but none of the providers can be installed > > - conflicting requests > > You can try to add to command line: > > --skip-broken to skip uninstallable packages > > I'm not brave enough to try the --skip-broken option. > I had to install plasma-workspace-x11 and use the X11 session to get a > functional System back. > > The following are some related reports: > https://retrace.fedoraproject.org/faf/reports/1245634/ > https://retrace.fedoraproject.org/faf/reports/1245856/ > > Thank you for your time :) You can downgrade safely with this oneliner without 'dnf downgrade': sudo dnf in koji && cd $(mktemp -d) && pwd && koji download-build -a noarch -a $(uname -m) qt6-qtwayland-6.9.1-1.fc42 && sudo dnf in ./qt6-qtwayland-6.9.1-1.fc42.*.rpm Worked for me, system is stable again
Or downgrading using the archive repos is also an option: sudo dnf install fedora-repos-archive sudo dnf config-manager setopt updates-archive.enabled=0 sudo dnf downgrade qt6-qtwayland-6.9.1-1.fc42 --enablerepo updates-archive
Lifesaver! I could downgrade with the fedora-repos-archive, and the problems disappeared. Thank you!
Downgraded with the help of koji above and lockscreen works again for me as well
Thanks, was also affected, dmesg was showing a segfault : kscreenlocker_g[26873]: segfault at 24bc ip 00007fa97386019d sp 00007fff3cfd5370 error 4 in libLayerShellQtInterface.so.6.4.1[319d,7fa97385d000+7000] Koji workaround applied. Thanks Szymon !
Upgraded severity to "Urgent" based on reports of impacts beyond the lockscreen (for example Thomas Hepp's here, and this user's on the KDE forum: https://discuss.kde.org/t/all-kde-apps-crash-upon-opening-interacting/36294/3).
Please, make this go away! - I was hit by this, reported in Fedora, found this thread, did the downgrade, and now System Settings don't start here. (My workaround was "Never" for the screen locker, and now I can't get it back to lock the screen.)
(In reply to pg_tips from comment #4) > Or downgrading using the archive repos is also an option: > > sudo dnf install fedora-repos-archive > sudo dnf config-manager setopt updates-archive.enabled=0 > sudo dnf downgrade qt6-qtwayland-6.9.1-1.fc42 --enablerepo updates-archive 1. TEMPORARY SOLUTION Downgrading using the archive repos fixed the issue for me as well: sudo dnf install fedora-repos-archive sudo dnf config-manager setopt updates-archive.enabled=0 sudo dnf downgrade qt6-qtwayland-6.9.1-1.fc42 --enablerepo updates-archive Thank you @pg_tips ! 2. ANNOYING SOLUTION Also can confirm that the CTRL+ALT+F3 worked, the error instruction message said F1 but that one didn't work for me. This worked to get back to my desktop: CTRL+ALT+F3 loginctl unlock-session 2 CTRL+D CTRL+ALT+F2 3. MY SYSTEM INFO Operating System: Fedora Linux 42 KDE Plasma Version: 6.4.1 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 Kernel Version: 6.15.3-200.fc42.x86_64 (64-bit)
(In reply to tttstr from comment #10) > (In reply to pg_tips from comment #4) > > Or downgrading using the archive repos is also an option: > > > > sudo dnf install fedora-repos-archive > > sudo dnf config-manager setopt updates-archive.enabled=0 > > sudo dnf downgrade qt6-qtwayland-6.9.1-1.fc42 --enablerepo updates-archive > > 1. TEMPORARY SOLUTION > > Downgrading using the archive repos fixed the issue for me as well: > > sudo dnf install fedora-repos-archive > sudo dnf config-manager setopt updates-archive.enabled=0 > sudo dnf downgrade qt6-qtwayland-6.9.1-1.fc42 --enablerepo updates-archive > > Thank you @pg_tips ! > > 2. ANNOYING SOLUTION > > Also can confirm that the CTRL+ALT+F3 worked, the error instruction message > said F1 but that one didn't work for me. This worked to get back to my > desktop: > > CTRL+ALT+F3 > loginctl unlock-session 2 > CTRL+D > CTRL+ALT+F2 > > 3. MY SYSTEM INFO > > Operating System: Fedora Linux 42 > KDE Plasma Version: 6.4.1 > KDE Frameworks Version: 6.15.0 > Qt Version: 6.9.1 > Kernel Version: 6.15.3-200.fc42.x86_64 (64-bit) If you want to prevent future automatic updates of qt6-qtwayland, you can run: sudo dnf versionlock add qt6-qtwayland And to later remove the lock: sudo dnf versionlock delete qt6-qtwayland
What would stop Fedora from rolling back to -1? What was trying to get fixed with -2? Was the changed, broken part found? What was changed?
Setting a wallpaper (per https://bugzilla.redhat.com/show_bug.cgi?id=2375328) fixes it so no need for a downgrade.
I suspect this might be an ABI breakage caused by a patch introduced in -2: https://src.fedoraproject.org/rpms/qt6-qtwayland/blob/f42/f/qtwayland-add-pointer-warp-support.patch#_236 (a new field pointerWarp was introduced which changed the layout of the QWaylandDisplay class). In order to fix the issue, the patch in question should either be reworked to preserve ABI compatibility or removed entirely. Rebuilding `layer-shell-qt` from source caused the issue to stop reproducing, confirming suspicions of ABI breakage.
(In reply to e.ohlms from comment #13) > Setting a wallpaper (per > https://bugzilla.redhat.com/show_bug.cgi?id=2375328) fixes it so no need for > a downgrade. That didn't fix it for me. Interestingly, it did seem to mitigate it for a few minutes - I was able to lock and unlock normally once or twice - but the issue quickly recurred. Only by downgrading was I able to eliminate the issue on my system.
(In reply to Myrrh Periwinkle from comment #14) > I suspect this might be an ABI breakage caused by a patch introduced in -2: > https://src.fedoraproject.org/rpms/qt6-qtwayland/blob/f42/f/qtwayland-add- > pointer-warp-support.patch#_236 (a new field pointerWarp was introduced > which changed the layout of the QWaylandDisplay class). > > In order to fix the issue, the patch in question should either be reworked > to preserve ABI compatibility or removed entirely. > > Rebuilding `layer-shell-qt` from source caused the issue to stop > reproducing, confirming suspicions of ABI breakage. Jan, what should we do here? We can try adjusting the patch or we can rebuild layer-shell-qt instead...
A related bug https://bugzilla.redhat.com/show_bug.cgi?id=2375438 appears to have been raised against layer-shell-qt. I don't have access to it, but I guess Red Hat folks may.
FEDORA-2025-6842ac8bfa (qt6-qtwayland-6.9.1-3.fc42) has been submitted as an update to Fedora 42. https://bodhi.fedoraproject.org/updates/FEDORA-2025-6842ac8bfa
(In reply to Fedora Update System from comment #18) > FEDORA-2025-6842ac8bfa (qt6-qtwayland-6.9.1-3.fc42) has been submitted as an > update to Fedora 42. > https://bodhi.fedoraproject.org/updates/FEDORA-2025-6842ac8bfa I tested this upgrade and it really fixed the bug for me, excellent! Operating System: Fedora Linux 42 KDE Plasma Version: 6.4.1 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 Kernel Version: 6.15.4-200.fc42.x86_64 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5700U with Radeon Graphics Memory: 24 GiB of RAM (22.8 GiB usable) Graphics Processor: AMD Radeon Graphics qt6-qtwayland-6.9.1-3.fc42
(In reply to Geraldo Simião from comment #19) > (In reply to Fedora Update System from comment #18) > > FEDORA-2025-6842ac8bfa (qt6-qtwayland-6.9.1-3.fc42) has been submitted as an > > update to Fedora 42. > > https://bodhi.fedoraproject.org/updates/FEDORA-2025-6842ac8bfa > > I tested this upgrade and it really fixed the bug for me, excellent! > > Operating System: Fedora Linux 42 > KDE Plasma Version: 6.4.1 > KDE Frameworks Version: 6.15.0 > Qt Version: 6.9.1 > Kernel Version: 6.15.4-200.fc42.x86_64 (64-bit) > Graphics Platform: Wayland > Processors: 16 × AMD Ryzen 7 5700U with Radeon Graphics > Memory: 24 GiB of RAM (22.8 GiB usable) > Graphics Processor: AMD Radeon Graphics > > qt6-qtwayland-6.9.1-3.fc42 https://kojipkgs.fedoraproject.org//packages/qt6-qtwayland/6.9.1/3.fc42/x86_64/qt6-qtwayland-6.9.1-3.fc42.x86_64.rpm worked for me as well. Saw a newer release (qt6-qtwayland-6.9.1-3.fc43) here, but haven't tested it yet: https://koji.fedoraproject.org/koji/packageinfo?packageID=33069
Is this the same bug as bug 2375429?
(In reply to Vedran Miletić from comment #21) > Is this the same bug as bug 2375429? I would bet yes, based on the details and stack trace in that bug.
*** Bug 2375429 has been marked as a duplicate of this bug. ***
*** Bug 2375596 has been marked as a duplicate of this bug. ***