pungi.global.log
[ERROR ] Compose run failed: ImageBuild task failed: 26639624. See /mnt/koji/compose/Fedora-Cloud-28-20180429.0/logs/aarch64-ppc64-ppc64le-s390x-x86_64/imagebuild-Cloud-Cloud_Base-qcow2-raw-xz.aarch64-ppc64-ppc64le-s390x-x86_64.log for more details.
looks like we'll need to use 'https://kojipkgs.fedoraproject.org/compose/updates/f28-updates/compose/Everything/$arch/os/' for the updates repo URLs too (so we can use the same url for primary and secondary arches).
https://pagure.io/pungi-fedora/pull-request/613#