$ git clone -n https://src.fedoraproject.org/rpms/root.git /var/lib/mock/f43-build-58883824-6569013/root/chroot_tmpdir/scmroot/root
Cloning into '/var/lib/mock/f43-build-58883824-6569013/root/chroot_tmpdir/scmroot/root'...
$ git fetch origin 920e7b25758bfd961c166ae8a12445c4ed047d6b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/root
 * [new ref]         920e7b25758bfd961c166ae8a12445c4ed047d6b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 920e7b2 Update to 6.34.08