$ git clone -n https://src.fedoraproject.org/rpms/kiwi.git /var/lib/mock/f40-build-803038-144164/root/chroot_tmpdir/scmroot/kiwi
Cloning into '/var/lib/mock/f40-build-803038-144164/root/chroot_tmpdir/scmroot/kiwi'...
$ git fetch origin 508c772358fc0aa4f576aa8198c6278d83a1e15e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kiwi
 * [new ref]         508c772358fc0aa4f576aa8198c6278d83a1e15e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 508c772 Add missing files to the file list