Still doesn’t work, sorry.
GZDoom g4.2.4 - 2019-11-02 21:34:26 +0100 - SDL version
Compiled on Dec 21 2019
M_LoadDefaults: Load system defaults.
gcl@evolv:~$ This application failed to start because it could not find or load the Qt platform plugin "xcb" in "".
Reinstalling the application may fix this problem.
Aborted