After updating KDE Plasma 5.25, several applications do not start automatically when a user login a desktop session on both openSUSE Tumbleweed and Leap 15.5. This issue affects input methods such as IBus and Fcitx, which are essential for us.

The cause of this problem is the systemd-xdg-autostart-generator. systemd-xdg-autostart-generator is a new mechanism to launch applications listed in autostart directories (e.g., /etc/xdg/autostart) at session startup. Instead of a desktop environment, systemd launches those applications as user services. Plasma adopted and started to use this mechanism by default since version 5.25.

However, due to the following problems, systemd-xdg-autostart-generator cannot start desktop files derived from a former version of openSUSE.

1. systemd-xdg-autostart-generator inappropriately ignores desktop files with X-GNOME-Autostart-Phase key
2. systemd-xdg-autostart-generator kills daemonized applications

In this talk, I will explain the following topics:

• A basic concept of Systemd user service and Systemd generator
• Technical details of those bugs of systemd-xdg-autostart-generator
• A root cause of Bug 2 and how state transition of a systemd service happens inside Systemd.
• A story until this problem is fixed in Leap 15.5