[Build] Append boost include dir only

src/CMakeLists.txt

@@ -21,7 +21,6 @@ dune_symlink_to_source_files("sand-wedge-data/boundaryconditions.py")
 dune_symlink_to_source_files("sand-wedge-data/parset.cfg")
 
 find_package(Boost REQUIRED system filesystem serialization)
-include_directories(${Boost_INCLUDE_DIR})
 
 # dataio.hh expects this to be set
 set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS "HAVE_BOOST_SERIALIZATION")
@@ -32,6 +31,8 @@ foreach(_dim 2 3)
   add_dune_pythonlibs_flags(${_target})
   add_dune_ug_flags(${_target})
 
+  set_property(TARGET ${_target} APPEND PROPERTY INCLUDE_DIRECTORIES ${Boost_INCLUDE_DIRS})
+
   target_link_libraries(${_target} ${Boost_FILESYSTEM_LIBRARY})
   target_link_libraries(${_target} ${Boost_SERIALIZATION_LIBRARY})
   target_link_libraries(${_target} ${Boost_SYSTEM_LIBRARY})