/usr/include/dune/localfunctions/dualmortarbasis/ is in libdune-localfunctions-dev 2.3.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dune/localfunctions/dualmortarbasis/dualp1/
/usr/include/dune/localfunctions/dualmortarbasis/dualp1.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualp1/dualp1localbasis.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualp1/dualp1localcoefficients.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualp1/dualp1localinterpolation.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualpq1factory.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualq1/
/usr/include/dune/localfunctions/dualmortarbasis/dualq1.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualq1/dualq1localbasis.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualq1/dualq1localcoefficients.hh
/usr/include/dune/localfunctions/dualmortarbasis/dualq1/dualq1localinterpolation.hh