$ git clone -n https://src.fedoraproject.org/rpms/machineball.git /var/lib/mock/f45-build-4355886-58359/root/chroot_tmpdir/scmroot/machineball
Cloning into '/var/lib/mock/f45-build-4355886-58359/root/chroot_tmpdir/scmroot/machineball'...
$ git fetch origin 84ef055ed4cc3e2357947895dd7989475bae739d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/machineball
 * [new ref]         84ef055ed4cc3e2357947895dd7989475bae739d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 84ef055 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild