$ git clone -n https://src.fedoraproject.org/rpms/rmol.git /var/lib/mock/f42-build-3348052-45005/root/chroot_tmpdir/scmroot/rmol
Cloning into '/var/lib/mock/f42-build-3348052-45005/root/chroot_tmpdir/scmroot/rmol'...
$ git fetch origin 066f19ccfbf9389c22ca623d49056df4eae95cc1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rmol
 * [new ref]         066f19ccfbf9389c22ca623d49056df4eae95cc1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 066f19c Upstream update