$ git clone -n https://src.fedoraproject.org/rpms/plasma-firewall.git /var/lib/mock/f42-build-side-1-3578394-46814/root/chroot_tmpdir/scmroot/plasma-firewall
Cloning into '/var/lib/mock/f42-build-side-1-3578394-46814/root/chroot_tmpdir/scmroot/plasma-firewall'...
$ git fetch origin 4ff3b7d28f7fa8858239b574ade37a240bd7118e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-firewall
 * [new ref]         4ff3b7d28f7fa8858239b574ade37a240bd7118e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4ff3b7d 6.4.1