STEPS TO REPRODUCE 1. Invoke "ssh root@localhost ~]#", whereby "root" is merely any account that is not the account that is logged-into directly. It need not be the superuser nor named specifically "root". OBSERVED RESULT Invocation of "root@BEEDELLROKEJULIANLOCKHART ~]# kcmshell5" presents "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: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb. Aborted (core dumped)" EXPECTED RESULT "kcmshell5 Usage: kcmshell5 [options] module A tool to start single system settings modules Options: -h, --help Displays help on commandline options. --help-all Displays help including Qt specific options. -v, --version Displays version information. --author Show author information. --license Show licence information. --desktopfile <file name> The base file name of the desktop entry for this application. --list List all possible modules --lang <language> Specify a particular language --silent Do not display main window --args <arguments> Arguments for the module --icon <icon> Use a specific icon for the window --caption <caption> Use a specific caption for the window Arguments: module Configuration module to open". SOFTWARE/OS VERSIONS Windows: Negative. macOS: Negative. Linux/KDE Plasma: Positive. KDE Plasma Version: 5.24.5. KDE Frameworks Version: 5.93.0. Qt Version: 5.15.3.
kcmshell shouldn't be doing anything special here as far as I remember. Can you confirm that it's working for other applications like systemsettings or dolphin?
(In reply to Aleix Pol from comment #1) > kcmshell shouldn't be doing anything special here as far as I remember. > > Can you confirm that it's working for other applications like systemsettings > or dolphin? No graphical software operates, but because kcmshell5 is textual, I consider this to be erroneous, because all alternative textual software operates correctly. Is this opinion mistaken?
kcmshell5 isn't textual, it opens a window with a specific configuration module. What are you trying to achieve?
(In reply to Aleix Pol from comment #3) > kcmshell5 isn't textual, it opens a window with a specific configuration > module. > > What are you trying to achieve? I want to list the KConfig modules that are installed by invoking "kcmshell5 -list". I am able to understand any inability to communicate with my display-server via SSH if instruct it invoke any of the modules.
*if I instruct it to Apologies.
You can try running it with QT_QPA_PLATFORM=offscreen. Alternatively you can connect with "ssh -X" for X11 forwarding.
(In reply to Aleix Pol from comment #6) > You can try running it with QT_QPA_PLATFORM=offscreen. > > Alternatively you can connect with "ssh -X" for X11 forwarding. Yes, that certainly remediates the problem, but not well, because kcmshell5 should not require a display-server to textually present which modules are available. Thanks, however.
I am not entirely sure that it should work. Can you please elaborate on the use-case?
(In reply to Aleix Pol from comment #8) > I am not entirely sure that it should work. Can you please elaborate on the > use-case? I want to run automated tests that ensure that everything is configured correctly on a remote machine and subsequently provide the output to my console. If, for instance, I want to do this via my smartphone, using SSH to invoke an X Session and then manually invoking a graphical terminal is entirely unnecessarily difficult, and anyway breaks the automation of the process.
This use case is too niche to do anything about it. Aleix already told you a workaround you can use