[trinity-users] /etc/alternatives/default-xsession.desktop is not tde.desktop

openSUSE 15.0

Prior version 42.3 had no such file /etc/alternatives/default-xsession.desktop.

What's the prescribed procedure to make tde the default desktop? I tried 'yast2 alternatives', but tde.desktop is not an offered option, even though it is present in /usr/share/xsessions/. yast2 alternatives offers only icewm-default and icewm-lite. Is this something that needs a bug filed? I don't see anything on point. If yes, in openSUSE tracker, or in TDE tracker? Is there some existing trinity rpm that needs to be installed to create it?