Para openSUSE Tumbleweed execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:brassh/openSUSE_Tumbleweed/home:brassh.repo
zypper refresh
zypper install unison
Para graphics execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:brassh/graphics/home:brassh.repo
zypper refresh
zypper install unison
Para 15.6 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:brassh/15.6/home:brassh.repo
zypper refresh
zypper install unison