/usr/share/dune/cmake/modules/ is in libdune-common-dev 2.4.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/dune/cmake/modules/AddGMPFlags.cmake
/usr/share/dune/cmake/modules/AddMETISFlags.cmake
/usr/share/dune/cmake/modules/AddPTScotchFlags.cmake
/usr/share/dune/cmake/modules/AddParMETISFlags.cmake
/usr/share/dune/cmake/modules/AddSuiteSparseFlags.cmake
/usr/share/dune/cmake/modules/AddUMFPackFlags.cmake
/usr/share/dune/cmake/modules/CheckCXX11Features.cmake
/usr/share/dune/cmake/modules/CheckForPthreads.c
/usr/share/dune/cmake/modules/DuneBoost.cmake
/usr/share/dune/cmake/modules/DuneCMakePackageConfigHelpers.cmake
/usr/share/dune/cmake/modules/DuneCommonMacros.cmake
/usr/share/dune/cmake/modules/DuneCxaDemangle.cmake
/usr/share/dune/cmake/modules/DuneDoc.cmake
/usr/share/dune/cmake/modules/DuneDoxygen.cmake
/usr/share/dune/cmake/modules/DuneEnableAllPackages.cmake
/usr/share/dune/cmake/modules/DuneMPI.cmake
/usr/share/dune/cmake/modules/DuneMacros.cmake
/usr/share/dune/cmake/modules/DunePkgConfig.cmake
/usr/share/dune/cmake/modules/DuneStreams.cmake
/usr/share/dune/cmake/modules/DuneSymlinkOrCopy.cmake
/usr/share/dune/cmake/modules/DuneTestMacros.cmake
/usr/share/dune/cmake/modules/DuneTests.cmake
/usr/share/dune/cmake/modules/FindBoostFusion.cmake
/usr/share/dune/cmake/modules/FindGMP.cmake
/usr/share/dune/cmake/modules/FindInkscape.cmake
/usr/share/dune/cmake/modules/FindMETIS.cmake
/usr/share/dune/cmake/modules/FindMProtect.cmake
/usr/share/dune/cmake/modules/FindPTScotch.cmake
/usr/share/dune/cmake/modules/FindParMETIS.cmake
/usr/share/dune/cmake/modules/FindSuiteSparse.cmake
/usr/share/dune/cmake/modules/FindThreadsCMake31.cmake
/usr/share/dune/cmake/modules/FindUMFPack.cmake
/usr/share/dune/cmake/modules/Headercheck.cmake
/usr/share/dune/cmake/modules/LanguageSupport.cmake
/usr/share/dune/cmake/modules/OverloadCompilerFlags.cmake
/usr/share/dune/cmake/modules/UseInkscape.cmake
/usr/share/dune/cmake/modules/UseLATEX.cmake