/usr/include/dune/grid/alugrid/3d/ is in libdune-grid-dev 2.3.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dune/grid/alugrid/3d/alu3dgridfactory.cc
/usr/include/dune/grid/alugrid/3d/alu3dgridfactory.hh
/usr/include/dune/grid/alugrid/3d/alu3dinclude.hh
/usr/include/dune/grid/alugrid/3d/alu3diterators.hh
/usr/include/dune/grid/alugrid/3d/alugrid.hh
/usr/include/dune/grid/alugrid/3d/capabilities.hh
/usr/include/dune/grid/alugrid/3d/datahandle.hh
/usr/include/dune/grid/alugrid/3d/entity.hh
/usr/include/dune/grid/alugrid/3d/entity_imp.cc
/usr/include/dune/grid/alugrid/3d/entity_inline.hh
/usr/include/dune/grid/alugrid/3d/entityseed.hh
/usr/include/dune/grid/alugrid/3d/faceutility.hh
/usr/include/dune/grid/alugrid/3d/faceutility_imp.cc
/usr/include/dune/grid/alugrid/3d/geometry.hh
/usr/include/dune/grid/alugrid/3d/geometry_imp.cc
/usr/include/dune/grid/alugrid/3d/grid.hh
/usr/include/dune/grid/alugrid/3d/grid_imp.cc
/usr/include/dune/grid/alugrid/3d/grid_inline.hh
/usr/include/dune/grid/alugrid/3d/indexsets.hh
/usr/include/dune/grid/alugrid/3d/iterator.cc
/usr/include/dune/grid/alugrid/3d/iterator.hh
/usr/include/dune/grid/alugrid/3d/iterator_imp.cc
/usr/include/dune/grid/alugrid/3d/lbdatahandle.hh
/usr/include/dune/grid/alugrid/3d/mappings.hh
/usr/include/dune/grid/alugrid/3d/mappings_imp.cc
/usr/include/dune/grid/alugrid/3d/topology.hh