$ git clone -n https://src.fedoraproject.org/rpms/layer-shell-qt.git /var/lib/mock/f42-bootstrap-3533727-46421/root/chroot_tmpdir/scmroot/layer-shell-qt
Cloning into '/var/lib/mock/f42-bootstrap-3533727-46421/root/chroot_tmpdir/scmroot/layer-shell-qt'...
$ git fetch origin f05f9b9cdaf7692c8514779132ea0599d5245a15:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/layer-shell-qt
 * [new ref]         f05f9b9cdaf7692c8514779132ea0599d5245a15 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f05f9b9 6.3.5