$ git clone -n https://src.fedoraproject.org/rpms/python-stack-data.git /var/lib/mock/f40-build-2204385-51958/root/chroot_tmpdir/scmroot/python-stack-data
Cloning into '/var/lib/mock/f40-build-2204385-51958/root/chroot_tmpdir/scmroot/python-stack-data'...
$ git fetch origin 69b998512e87c02a0fe10160fcc26804367b7684:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-stack-data
 * [new ref]         69b998512e87c02a0fe10160fcc26804367b7684 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 69b9985 Update to 0.6.3 (rhbz#2241507)