At the moment trying to login through SLIM (same with SDDM) into LXDE you get the message "Failed to execute login command" for about 2 seconds, then the X session terminates and your are back at SLIM.
Effectively through the login managers we have, LXDE is not usable at the moment. I haven't tested using just "startx". I open this bug so that it can be referenced and is visible. To me it is known since I've sent in the meta package for LXDE. -- PGP and more: https://people.pragmatique.xyz/ng0/
