Para openSUSE Leap 15.6 corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:Herbster0815:pihole/openSUSE_Leap_15.6/home:Herbster0815:pihole.repo
zypper refresh
zypper install protobuf-c
Para openSUSE Leap 15.5 corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:Herbster0815:pihole/openSUSE_Leap_15.5/home:Herbster0815:pihole.repo
zypper refresh
zypper install protobuf-c
Para openSUSE Leap 15.4 corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:Herbster0815:pihole/openSUSE_Leap_15.4/home:Herbster0815:pihole.repo
zypper refresh
zypper install protobuf-c