On Slackware systemd is not available, so always behave as if -U was specified.
Also try to autodetect availability of systemd during make, and behave accordingly. This part should be tested on a system with systemd, as I'm not sure it works correctly.
On Slackware systemd is not available, so always behave as if -U was specified.
Also try to autodetect availability of systemd during make, and behave accordingly. This part should be tested on a system with systemd, as I'm not sure it works correctly.