$ git clone -n https://src.fedoraproject.org/rpms/arj.git /var/lib/mock/f41-build-797426-13658/root/chroot_tmpdir/scmroot/arj
Cloning into '/var/lib/mock/f41-build-797426-13658/root/chroot_tmpdir/scmroot/arj'...
$ git fetch origin ef454a53571645eea4679a36f3d9c38a609fe2fa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/arj
 * [new ref]         ef454a53571645eea4679a36f3d9c38a609fe2fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ef454a5 Eliminate use of obsolete %patchN syntax (#2283636)