Can you guys try to install the latest harbour-containers release (as we did before), then replace daemon.py with the one on my fork (same as before too), and then also replace the content of /usr/share/harbour-containers/scripts/guest/setups/debian.sh by that of this version, and only after that try to create a new Debian Sid container?
[defaultuser@Xperia10 ~]$ /usr/bin/qxdisplay --wayland-socket-name "../../display/wayland-container-0"
[D] unknown:0 - Using Wayland-EGL [D] unknown:0 - Specified Desktop file does not exist "/usr/sha re/applications/qxdisplay.desktop" [W] unknown:0 - Theme dir "/usr/share/themes/jolla/meegotouch/z 1.5/" does not exist [W] unknown:0 - Theme dir "/usr/share/themes/jolla/meegotouch/z 1.5/" does not exist