On my Xenial test system, I've got already gdm3 installed. Now I'd like to install the lightdm package as well. When I do so, it asks which default display manager should be used:
I need to avoid this question (going to install those packages with Chef). How do I do that?
With debconf-get-selections, I found:
$ debconf-get-selections | grep lightdm
# Choices: gdm3, lightdm
lightdm shared/default-x-display-manager select gdm3
lightdm lightdm/daemon_name string /usr/sbin/lightdm
Based on that, I created a file with an answer and gave it to debconf-set-selections:
$ cat /tmp/lightdm
lightdm shared/default-x-display-manager select lightdm
$ sudo debconf-set-selections -v /tmp/lightdm
info: Trying to set 'shared/default-x-display-manager' [select] to 'lightdm'
info: Loading answer for 'shared/default-x-display-manager'
But when I now run apt install lightdm, it still asks this question.
Why is it still asking that question and how can I avoid that?
debconffrontend mode to noninteractive as shown here apt-get install without debconf prompt – steeldriver Aug 25 '16 at 12:28