В Плазме на Манджаро (только на ней?) не запускаются графические приложения от рута.
Через sudo:
[xxx@xxxxxxx xxx]$ sudo kwrite
[sudo] пароль для xxx:
Executing KWrite with sudo is not possible due to unfixable security vulnerabilities.
# kwrite
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: wayland-org.kde.kwin.qpa, dxcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.
Аварийный останов (стек памяти сброшен на диск)