HDFFV-10979 fix global name clash

config/cmake_ext_mod/HDFMacros.cmake

@@ -372,8 +372,13 @@ macro (HDF_DIR_PATHS package_prefix)
     endif ()
   endif ()
 
+  # Always use full RPATH, i.e. don't skip the full RPATH for the build tree
   set (CMAKE_SKIP_BUILD_RPATH  FALSE)
+  # when building, don't use the install RPATH already
+  # (but later on when installing)
   set (CMAKE_INSTALL_RPATH_USE_LINK_PATH  FALSE)
+  # add the automatically determined parts of the RPATH
+  # which point to directories outside the build tree to the install RPATH
   set (CMAKE_BUILD_WITH_INSTALL_RPATH ON)
   if (APPLE)
     set (CMAKE_INSTALL_NAME_DIR "@rpath")