At a non-systemd system the following (auth.log) warning might be suppressed : PAM unable to dlopen(/lib64/security/pam_systemd.so): /lib64/security/pam_systemd.so: cannot open shared object file: No such file or directory by adding a '-' in front of /etc/pam.d/sddm-greeter -session optional pam_systemd.so
*** This bug has been marked as a duplicate of bug 576536 ***