/usr/include/dune/istl/paamg/ is in libdune-istl-dev 2.3.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dune/istl/paamg/aggregates.hh
/usr/include/dune/istl/paamg/amg.hh
/usr/include/dune/istl/paamg/combinedfunctor.hh
/usr/include/dune/istl/paamg/construction.hh
/usr/include/dune/istl/paamg/dependency.hh
/usr/include/dune/istl/paamg/fastamg.hh
/usr/include/dune/istl/paamg/fastamgsmoother.hh
/usr/include/dune/istl/paamg/galerkin.hh
/usr/include/dune/istl/paamg/globalaggregates.hh
/usr/include/dune/istl/paamg/graph.hh
/usr/include/dune/istl/paamg/graphcreator.hh
/usr/include/dune/istl/paamg/hierarchy.hh
/usr/include/dune/istl/paamg/indicescoarsener.hh
/usr/include/dune/istl/paamg/kamg.hh
/usr/include/dune/istl/paamg/parameters.hh
/usr/include/dune/istl/paamg/pinfo.hh
/usr/include/dune/istl/paamg/properties.hh
/usr/include/dune/istl/paamg/renumberer.hh
/usr/include/dune/istl/paamg/smoother.hh
/usr/include/dune/istl/paamg/transfer.hh
/usr/include/dune/istl/paamg/twolevelmethod.hh