rubygem-tetra from home:dgedon:branches:devel:languages:ruby:extensions project

Select Your Operating System

For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:dgedon:branches:devel:languages:ruby:extensions/15.6/home:dgedon:branches:devel:languages:ruby:extensions.repo
zypper refresh
zypper install rubygem-tetra