$ git clone -n https://src.fedoraproject.org/rpms/clapper.git /var/lib/mock/f42-build-side-1-3562220-46722/root/chroot_tmpdir/scmroot/clapper
Cloning into '/var/lib/mock/f42-build-side-1-3562220-46722/root/chroot_tmpdir/scmroot/clapper'...
$ git fetch origin 4b83983b08f28b230217a7723fe82254a1e8fdb5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/clapper
 * [new ref]         4b83983b08f28b230217a7723fe82254a1e8fdb5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4b83983 update to 0.8.0 (resolves rhbz#2339069)