The shipped unit's PartOf=punktfunk-kde-session.service covers the
APPLIANCE route, where we start the compositor ourselves. A host on a
machine somebody logs into has no such unit: when Plasma or GNOME
restarts, the daemon keeps running while holding a Wayland socket and a
portal D-Bus connection that both died with the old compositor, and it
cannot recover either in-process. It fails quietly — the host still
listens, still answers, and every session it then serves dies at capture.
A host that mirrors a monitor idles for days between sessions, which is
the shape that finds this at the worst moment.
The drop-in binds the host to graphical-session.target: PartOf takes it
down with the session, WantedBy brings it back with the new one. Shipped
under /usr/share rather than as an active drop-in, because it is wrong
for the appliance route (which may never reach that target at all, and
would then leave the host permanently stopped) — the operator opts in.
Closes the restart half of design/per-monitor-portal-capture.md §6.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
