$ git clone -n https://src.fedoraproject.org/rpms/ipv6calc.git /var/lib/mock/f41-build-846130-162970/root/chroot_tmpdir/scmroot/ipv6calc
Cloning into '/var/lib/mock/f41-build-846130-162970/root/chroot_tmpdir/scmroot/ipv6calc'...
$ git fetch origin 5fa80bb362d897b8cc8bc36d5e84797fc283d2d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ipv6calc
 * [new ref]         5fa80bb362d897b8cc8bc36d5e84797fc283d2d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5fa80bb Final release 4.2.1