$ git clone -n https://src.fedoraproject.org/rpms/mapnik.git /var/lib/mock/f41-build-812184-147723/root/chroot_tmpdir/scmroot/mapnik
Cloning into '/var/lib/mock/f41-build-812184-147723/root/chroot_tmpdir/scmroot/mapnik'...
$ git fetch origin 969b087312f5cbbeb59d8ba460c7c10ba4c239d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mapnik
 * [new ref]         969b087312f5cbbeb59d8ba460c7c10ba4c239d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 969b087 Rebuild (gdal)