$ git clone -n https://src.fedoraproject.org/rpms/fftw.git /var/lib/mock/f40-build-2198137-51688/root/chroot_tmpdir/scmroot/fftw
Cloning into '/var/lib/mock/f40-build-2198137-51688/root/chroot_tmpdir/scmroot/fftw'...
$ git fetch origin 1f685fa2628e8eb660e945acb14daf5b20f9dbb4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fftw
 * [new ref]         1f685fa2628e8eb660e945acb14daf5b20f9dbb4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1f685fa Merge #11 `migrate to SPDX license format`