$ git clone -n https://src.fedoraproject.org/rpms/rocksndiamonds.git /var/lib/mock/f45-build-34581-688/root/chroot_tmpdir/scmroot/rocksndiamonds
Cloning into '/var/lib/mock/f45-build-34581-688/root/chroot_tmpdir/scmroot/rocksndiamonds'...
$ git fetch origin c059dc3a07656273c7c5ec1639d4a2a0175fa1a1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rocksndiamonds
 * [new ref]         c059dc3a07656273c7c5ec1639d4a2a0175fa1a1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c059dc3 4.4.2.4