$ git clone -n https://src.fedoraproject.org/rpms/cppzmq.git /var/lib/mock/f40-build-2240187-53632/root/chroot_tmpdir/scmroot/cppzmq
Cloning into '/var/lib/mock/f40-build-2240187-53632/root/chroot_tmpdir/scmroot/cppzmq'...
$ git fetch origin 661b171f17a602f12dc3b6a6600cd70ac9f3385f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cppzmq
 * [new ref]         661b171f17a602f12dc3b6a6600cd70ac9f3385f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 661b171 Ignored tarballs/