$ git clone -n https://src.fedoraproject.org/rpms/collectd.git /var/lib/mock/f40-build-2692757-68252/root/chroot_tmpdir/scmroot/collectd
Cloning into '/var/lib/mock/f40-build-2692757-68252/root/chroot_tmpdir/scmroot/collectd'...
$ git fetch origin 1e0cf693e72d329ba406289e81cff481ca9f99fc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/collectd
 * [new ref]         1e0cf693e72d329ba406289e81cff481ca9f99fc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1e0cf69 rebuild for updated nut