$ git clone -n https://src.fedoraproject.org/rpms/root.git /var/lib/mock/f38-build-side-42-init-devel-1345417-30695/root/chroot_tmpdir/scmroot/root
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1345417-30695/root/chroot_tmpdir/scmroot/root'...
$ git fetch origin 79c12df5ba2db9028fcbc674d5ed32cb1e653eb8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/root
 * [new ref]         79c12df5ba2db9028fcbc674d5ed32cb1e653eb8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 79c12df Update to 6.28.06