$ git clone -n https://src.fedoraproject.org/rpms/nftables.git /var/lib/mock/f42-build-863148-171455/root/chroot_tmpdir/scmroot/nftables
Cloning into '/var/lib/mock/f42-build-863148-171455/root/chroot_tmpdir/scmroot/nftables'...
$ git fetch origin b587396bc238ea57b705493cc4edaf89f5a1f9e3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nftables
 * [new ref]         b587396bc238ea57b705493cc4edaf89f5a1f9e3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b587396 Rebuild for Jansson 2.14