xdg-settings attempts to call kde5-config instead of kf5-config
when KDE_SESSION_VERSION is 5 the relevant script is called
kde5-config, from what I've been able to gather. I can confirm that
kf5-config --path config produces a
:-delimited list of paths that contain kde config files including the
kdeglobals file that I see this function trying to access in my current workflow.