Para openSUSE Factory+GNOME Factory corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:Apps/openSUSE_Factory+GNOME_Factory/GNOME:Apps.repo
zypper refresh
zypper install gcstar
Para openSUSE Factory corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:Apps/openSUSE_Factory/GNOME:Apps.repo
zypper refresh
zypper install gcstar
Para 15.6 corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:Apps/15.6/GNOME:Apps.repo
zypper refresh
zypper install gcstar