Para SLE 15 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:steffens:SmartClient:server/SLE_15/home:steffens:SmartClient:server.repo
zypper refresh
zypper install perl-Unix-Syslog
Para SLE 12 SP4 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:steffens:SmartClient:server/SLE_12_SP4/home:steffens:SmartClient:server.repo
zypper refresh
zypper install perl-Unix-Syslog
Para SLE 12 SP1 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:steffens:SmartClient:server/SLE_12_SP1/home:steffens:SmartClient:server.repo
zypper refresh
zypper install perl-Unix-Syslog