For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Virtualization:Tests/openSUSE_Tumbleweed/Virtualization:Tests.repo
zypper refresh
zypper install perl-Test-Harness
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Virtualization:Tests/openSUSE_Factory/Virtualization:Tests.repo
zypper refresh
zypper install perl-Test-Harness
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Virtualization:Tests/15.5/Virtualization:Tests.repo
zypper refresh
zypper install perl-Test-Harness