I am trying to install kde-plasma-desktop non-interactively. It installs both lightdm and kdm packages. I am using debconf-set-selections to set the "shared/default-x-display-manager" question for both kdm and lightdm before running apt-get, to avoid interaction. Unfortunately the dialog is still presented to choose kdm or lightdm. If I use "DEBIAN_FRONTEND=non-interactive apt-get install" I avoid the interaction, but the configuration database values are overwritten to prefer kdm. Reproducible: Always Steps to Reproduce: # debconf-set-selections << ENDIT kdm shared/default-x-display-manager select lightdm lightdm shared/default-x-display-manager select lightdm ENDIT # debconf-get-selections | grep x-display-manager kdm shared/default-x-display-manager select lightdm lightdm shared/default-x-display-manager select lightdm # DEBIAN_FRONTEND=noninteractive apt-get install kde-plasma-desktop ... Actual Results: # debconf-get-selections | grep x-display-manager kdm shared/default-x-display-manager select kdm lightdm shared/default-x-display-manager select kdm The file /etc/X11/default-display-manager contains "/usr/bin/kdm" Expected Results: # debconf-get-selections | grep x-display-manager kdm shared/default-x-display-manager select lightdm lightdm shared/default-x-display-manager select lightdm The file /etc/X11/default-display-manager contains "/usr/bin/lightdm"
For the record, this appears to be version 4.11.11, but that's not an option in the bug selection dialog. Actual package name is kdm_4%3a4.11.11-0ubuntu0.1_amd64.deb
I did a couple of experiments. After installing kde-plasma-desktop, I removed just kdm, set the database to select lightdm, removed /etc/X11/default-display-manager, and then reinstalled kdm with "DEBIAN_FRONTEND=noninteractive apt-get install kdm". This time it correctly read the package database, and restored /etc/X11/default-display-manager to specify lightdm. I tried the same thing with removing/reinstalling lightdm, and had the same correct result (lightdm). I even tried removing both, and then installing both together. That also has the correct result. So I don't know what it is about installing kde-plasma-desktop that produces the wrong result here.
You should better report this to your distribution, I'd say. KDE has no influence how they package the software. And debconf and that "configuration dialog" is highly specific to Debian-based systems IIANM, and totally unrelated to KDE anyway.