a service template (foo@.service) can only be used with a parameter
on the commandline but will not work in the specfile without the parameter.

%service_add_pre qemu-ga@.service
%service_del_preun qemu-ga@.service
%service_add_post qemu-ga@.service
%service_del_postun qemu-ga@.service

(1/1) Removing qemu-guest-agent-2.11.1-4.6.x86_64
........................[done]
Additional rpm output:
Failed to stop qemu-ga@.service: Unit name qemu-ga@.service is missing the
instance name.
See system logs and 'systemctl status qemu-ga@.service' for details.
Failed to get load state of qemu-ga@.service: Unit name qemu-ga@.service is
neither a valid invocation ID nor unit name.