Comment # 2 on bug 996220 from Wolfgang Bauer

(In reply to Robby Engelmann from comment #0)
> using sddm 0.14 (frameworks repo) after each logout-login a sddm-directory
> in home/.local/share/ is created which results in am empty theme pane in
> plasma 5.7 sddm_kcm
> 
> This is not the case for sddm 0.13.

Starting with 0.14, sddm creates the user session log file as
~/.local/share/sddm/xorg-session.log by default.

It can be set via the SessionLogFile option, from "man sddm.conf":
       SessionLogFile=
              Path to the user session log file, relative to the  home  direc-
              tory.  Default value is ".local/share/sddm/xorg-session.log".

Maybe we should set it to ~/.xsession-errors by default, would be more in line
with previous versions and other display managers.
The problem is just that this won't affect existing installations...
For that we probably should patch sddm to change the default.

That the KCM doesn't show any themes when ~/.local/share/sddm/ exists is rather
a bug in the KCM though IMHO, which is provided by KDE, not SDDM. It should
show themes in ~/.local/share/sddm/themes/ in *addition* to, not instead of
those in /usr/share/sddm/themes/ as it apparently does.

But I see in your SDDM bug report that the KDE maintainer has been notified
already anyway.