$ git clone -n https://src.fedoraproject.org/rpms/lua5.1-lpeg.git /var/lib/mock/f39-build-1601046-38554/root/chroot_tmpdir/scmroot/lua5.1-lpeg
Cloning into '/var/lib/mock/f39-build-1601046-38554/root/chroot_tmpdir/scmroot/lua5.1-lpeg'...
$ git fetch origin fdf33dff7c8725356d7d01bee19c8f82facbf925:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lua5.1-lpeg
 * [new ref]         fdf33dff7c8725356d7d01bee19c8f82facbf925 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fdf33df Added the README