/usr/include/polymake/external/permlib/search/ is in libpolymake-dev-common 3.2r2-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/polymake/external/permlib/search/base_search.h
/usr/include/polymake/external/permlib/search/classic/
/usr/include/polymake/external/permlib/search/classic/backtrack_search.h
/usr/include/polymake/external/permlib/search/classic/intersection_search.h
/usr/include/polymake/external/permlib/search/classic/lex_smaller_image_search.h
/usr/include/polymake/external/permlib/search/classic/set_image_search.h
/usr/include/polymake/external/permlib/search/classic/set_stabilizer_search.h
/usr/include/polymake/external/permlib/search/dset.h
/usr/include/polymake/external/permlib/search/orbit_lex_min_search.h
/usr/include/polymake/external/permlib/search/partition/
/usr/include/polymake/external/permlib/search/partition/backtrack_refinement.h
/usr/include/polymake/external/permlib/search/partition/group_refinement.h
/usr/include/polymake/external/permlib/search/partition/intersection_search.h
/usr/include/polymake/external/permlib/search/partition/matrix_automorphism_search.h
/usr/include/polymake/external/permlib/search/partition/matrix_refinement1.h
/usr/include/polymake/external/permlib/search/partition/matrix_refinement2.h
/usr/include/polymake/external/permlib/search/partition/partition.h
/usr/include/polymake/external/permlib/search/partition/r_base.h
/usr/include/polymake/external/permlib/search/partition/refinement.h
/usr/include/polymake/external/permlib/search/partition/refinement_family.h
/usr/include/polymake/external/permlib/search/partition/set_image_refinement.h
/usr/include/polymake/external/permlib/search/partition/set_image_search.h
/usr/include/polymake/external/permlib/search/partition/set_stabilize_refinement.h
/usr/include/polymake/external/permlib/search/partition/set_stabilizer_search.h
/usr/include/polymake/external/permlib/search/partition/vector_stabilizer_search.h