$ git clone -n https://src.fedoraproject.org/rpms/cantor.git /var/lib/mock/f42-build-3357772-45030/root/chroot_tmpdir/scmroot/cantor
Cloning into '/var/lib/mock/f42-build-3357772-45030/root/chroot_tmpdir/scmroot/cantor'...
$ git fetch origin bb6846bc49e7584c388ffcce73ec3dfdcbfde0f7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cantor
 * [new ref]         bb6846bc49e7584c388ffcce73ec3dfdcbfde0f7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bb6846b Fix duplicate packaging