$ git clone -n https://src.fedoraproject.org/rpms/mapnik.git /var/lib/mock/f41-build-845240-162678/root/chroot_tmpdir/scmroot/mapnik
Cloning into '/var/lib/mock/f41-build-845240-162678/root/chroot_tmpdir/scmroot/mapnik'...
$ git fetch origin 6216a832bd4779947763621b05e984e1f6d0f618:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mapnik
 * [new ref]         6216a832bd4779947763621b05e984e1f6d0f618 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6216a83 Correct library soname to drop patch number