$ git clone -n https://github.com/xcp-ng-rpms/iperf3.git /var/lib/mock/v8.3-u-pcoval2-10570-29125/root/chroot_tmpdir/scmroot/iperf3
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10570-29125/root/chroot_tmpdir/scmroot/iperf3'...
$ git fetch origin 32b839523ec201f5f04e029fcdebf52667fc48b3:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/iperf3
 * [new ref]         32b839523ec201f5f04e029fcdebf52667fc48b3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 32b8395 bump release for test build