after changing pungi to put $basearch in the url for livemedia tasks we ended up with a $basearch dir in the variant https://kojipkgs.fedoraproject.org/compose/rawhide/Fedora-24-20160218.n.0/compose/Workstation/ has an example
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/pungi/pungi/issues/164
Please continue any further discussion there.