Created attachment 190739 [details] Backtrace+kwin buildinfo+systeminfo separated by ##### kwin_wayland crashes on the first keypress after startup (and restarts on every subsequent keypress) when XKBVARIANT=latin is set in /etc/vconsole.conf, because de(latin) is not a valid XKB variant. Critically, kwin_wayland emits no error or warning related to the invalid keymap — making the root cause extremely difficult to diagnose without external help. The crash is fully reproducible via XKB_DEFAULT_VARIANT=latin startplasma-wayland. The core issue is twofold: the crash itself, and the complete absence of any actionable error output from kwin_wayland that would point a user toward the actual cause. Steps to Reproduce: 1a. Set XKBVARIANT=latin in /etc/vconsole.conf (results in an invalid XKB keymap entry de(latin)) Start a Plasma Wayland session via either: 2a. exec startplasma-wayland from a TTY (with DBus already started by systemd-logind), or SDDM display manager 3a. Observe that kwin_wayland crashes on the first keypress and restarts on every subsequent keypress 1b. Launch plasma from cli via 'XKB_DEFAULT_VARIANT=latin startplasma-wayland' Attachments: - Backtrace (compiled with debug flags for kwin, libxkbcommon, qtbase - thanks to sam_ from #gentoo) - KWin build configuration - Plasma Systeminfo
> Critically, kwin_wayland emits no error or warning related to the invalid keymap It does print warnings, see https://invent.kde.org/plasma/kwin/-/blob/master/src/xkb.cpp#L546
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/8989
(In reply to Nicolas Fella from comment #1) > > Critically, kwin_wayland emits no error or warning related to the invalid keymap > > It does print warnings, see > https://invent.kde.org/plasma/kwin/-/blob/master/src/xkb.cpp#L546 I did re-check journalctl and I now do see this message indeed. Hopefully this will help somebody else. Thanks for the quick review/commit
Git commit 1c1329945cc6a39e9ad4d2b775802bfe07e56904 by Nicolas Fella. Committed on 18/03/2026 at 09:45. Pushed by nicolasfella into branch 'master'. A11yKeyboardMonitor: Don't crash when XKB state is null M +4 -0 src/a11ykeyboardmonitor.cpp https://invent.kde.org/plasma/kwin/-/commit/1c1329945cc6a39e9ad4d2b775802bfe07e56904
Git commit 0a513d4b404777399de369ec9d919b6956f7ba5a by Nicolas Fella. Committed on 18/03/2026 at 10:09. Pushed by nicolasfella into branch 'Plasma/6.6'. A11yKeyboardMonitor: Don't crash when XKB state is null (cherry picked from commit 1c1329945cc6a39e9ad4d2b775802bfe07e56904) Co-authored-by: Nicolas Fella <nicolas.fella@gmx.de> M +4 -0 src/a11ykeyboardmonitor.cpp https://invent.kde.org/plasma/kwin/-/commit/0a513d4b404777399de369ec9d919b6956f7ba5a
*** Bug 518540 has been marked as a duplicate of this bug. ***
*** Bug 509637 has been marked as a duplicate of this bug. ***