EPEL-8.0 supports IBM Z

The Extra Packages for Enterprise Linux (EPEL) repository now supports Red Hat Enterprise Linux 8 (RHEL 8), including the IBM Z/s390x platform. See the announcement here, and the list of available packages here.
To install, simply run

   $ yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm

Note: As of this writing, the RHEL 8.1 beta releases do not work with EPEL yet, due to a bug. However, the RHEL 8 release was found to work with EPEL just fine.