$ git clone -n https://src.fedoraproject.org/rpms/iperf.git /var/lib/mock/f45-build-14192-457/root/chroot_tmpdir/scmroot/iperf
Cloning into '/var/lib/mock/f45-build-14192-457/root/chroot_tmpdir/scmroot/iperf'...
$ git fetch origin 13d448f7a8e546ae57328532503e4ac8428bbe26:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/iperf
 * [new ref]         13d448f7a8e546ae57328532503e4ac8428bbe26 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 13d448f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild