$ git clone -n https://src.fedoraproject.org/rpms/fedora-eln-backgrounds.git /var/lib/mock/f45-build-8856-396/root/chroot_tmpdir/scmroot/fedora-eln-backgrounds
Cloning into '/var/lib/mock/f45-build-8856-396/root/chroot_tmpdir/scmroot/fedora-eln-backgrounds'...
$ git fetch origin dc2771b7491131dfdfdb220af5c42c391ce7a061:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fedora-eln-backgrounds
 * [new ref]         dc2771b7491131dfdfdb220af5c42c391ce7a061 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dc2771b Revert "Also Obsolete/Provide desktop-backgrounds-basic"