I'm trying to use systemd as a XDG Autostart manager for WMs that does not provide builtin support for autostart entries. At first, I simply tried to `systemctl --user start` the target inside the window manager. However, it quickly turned out that the target cannot and not meant to be manually started and instead should be specified as a `Wants=` dependency.
But how exactly?
1. Which unit should be linked to the autostart target as `Wants=` dependency?
Should the user / WM author create / provide another user unit just so that it can pull in the autostart target?
2. Looking at the source code, it seems that `_OnlyShowIn_=` detection relies on the $XDG_CURRENT_DESKTOP environment.
Whose responsibility is it to set this variable? Display manager? Window manager? Or by the user?
The man pages of `systemd.special` and `systemd-xdg-autostart-generator` were the only documentations I could find about this feature, and I'm still not sure what I'm supposed to do.
Thanks in advance for your help.
