I recently migrated to systemd using the plasma5 systemd profile. After remerging world, cups turned out not to have the systemd use flag set (I did not have systemd as a global flag). I think it should be, so that the global flag is unnecessary and this is covered by the profile.
profiles/targets/systemd/make.defaults already has systemd as a global use flag set by profile. Check your local files in /etc/portage/ as you probably are overriding that.
Maybe cups isn't in your world. Was it actually rebuilt with the world remerge?
(In reply to NP-Hardass from comment #1) > profiles/targets/systemd/make.defaults already has systemd as a global use > flag set by profile. Check your local files in /etc/portage/ as you > probably are overriding that. Checked, no override found. (In reply to Jouni Kosonen from comment #2) > Maybe cups isn't in your world. Was it actually rebuilt with the world > remerge? It is (now?). In any case, I unset the make.conf use flag and tried to re-emerge and the problem did not pop up again. I'm closing as WORKSFORME. Sorry for the noise.