LightDM - Pruning / purging multiple unecessary WM options

[1fallen]

Without reading the source to lightdm (and / or the greeter in use - probably lightdm-gtk-greeter) very closely, I can only assume that lightdm reads some additional desktop files beyond those in /usr/share/xsessions/. I'd try something like

find / -path /usr/share/applications -prune -o -path /usr/share/xsessions -prune -o -path $HOME/.local/share/applications -prune -o -iname '*.desktop'

This should find any .desktop files outside the three locations given (we know there are desktop files there and they are not the ones we are after). That will still give a lot of false hits, but if there are desktop files which are responsible for the sessions you see, they should be among the results. Might want to either pipe this into less or sent error output to /dev/null for the sake of readability ...

Holger

+1 that would make sense to me.
Now for a fresh look
This is a very very Beta Arch Distro, Holgre might have the look needed with (- probably lightdm-gtk-greeter) But mine again just to test against gnome sessions as well):

cd /usr/share/xsessions && ls
gnome.desktop  gnome-xorg.desktop  onyx.desktop  xfce.desktop

I'm just going with what has already been suggested:

I'm keeping the "onyx.desktop" that's the desktop I'm currently testing now.
One item at a time:

sudo mv /usr/share/xsessions/gnome.desktop gnome.desktop.bk
###
sudo mv /usr/share/xsessions/gnome-xorg.desktop gnome-xorg.desktop.bk

Now I always look:

cd    /usr/share/xsessions && ls
gnome.desktop.bk  gnome-xorg.desktop.bk  onyx.desktop  xfce.desktop

Just for fun I'll move those two elswhere:

sudo mv gnome.desktop.bk /home/me/Documents
###
sudo mv gnome-xorg.desktop.bk /home/me/Documents

Another look:

ls
onyx.desktop  xfce.desktop

Even before the move to Documents I had only the two sessions showing.
I never use " lightdm-gtk-greeter" i remember 8 years back this was a buggy choice so I've not used it since.

[coffeecat]

Ok it is time for me to come clean. I am not actually running Ubuntu. I am not even running another Linux distro with advanced package tool. I'm running Manjaro.

@Drone4four, you originally posted in the General Help sub-forum, whose strapline clearly states, "All your general support questions for Ubuntu, Kubuntu, Edubuntu, Xubuntu, Lubuntu, Ubuntu Mate, Ubuntu Budgie, Ubuntu Studio and Ubuntu Kylin.". Unsurprisingly, Manjaro is not amongst them.

Thread moved to Arch and derivatives sub-forum.

Although we provide specific sub-forums for non-Ubuntu distros, this is merely a convenience for members - as 1fallen says, you may be better off seeking help in the Manjaro forum.

[Drone4four]

I'd try something like

find / -path /usr/share/applications -prune -o -path /usr/share/xsessions -prune -o -path $HOME/.local/share/applications -prune -o -iname '*.desktop'

This should find any .desktop files outside the three locations given (we know there are desktop files there and they are not the ones we are after). That will still give a lot of false hits, but if there are desktop files which are responsible for the sessions you see, they should be among the results. Might want to either pipe this into less or sent error output to /dev/null for the sake of readability

This was a stroke of genius, @Holger_Gehrke. Thank you.

Since I wasn't sure how to pipe or highlight the right files, I exported your command into a .txt file in my home directory. I used this:

sudo find / -path /usr/share/applications -prune -o -path /usr/share/xsessions -prune -o -path $HOME/.local/share/applications -prune -o -iname '*.desktop' > xsession-search-2023sep10.txt

Next I opened `xsession-search-2023sep10.txt` in gedit. The file was some 740 lines long. Then did a Ctrl + F for: `classic.desktop` which referred to this location:

/usr/share/wayland-sessions/gnome.desktop
/usr/share/wayland-sessions/gnome-classic.desktop
/usr/share/wayland-sessions/gnome-classic-wayland.desktop
/usr/share/wayland-sessions/gnome-wayland.desktop

It appears wayland-sessions serves the same purpose as xsessions. So I proceeded to backup files: gnome.desktop, gnome-classic.desktop, gnome-classic-wayland.desktop. And Eureka! It works! See here: https://i.imgur.com/WLIhgCA.jpg

Mission Accomplished. Thank you Holger.