message: cxx: clean up
diff: @@ -274,20 +274,17 @@ class Config:
  self.__local_includes.add(path)
  self._includes[path] = None
  -
  def add_system_include_path(self, path):
  path = Path(path)
  # Never include those.
  # FIXME: Unix only
  - if path == Path('/include') or path == Path('/usr/include'):
  - return
  + if path not in [Path('/include'), Path('/usr/include')]:
  if not path.absolute():
  path = drake.path_build() / path
  path = path.canonize()
  self.__system_includes.add(path)
  self._includes[path] = None
  -
  def include_path(self):
  return list(self._includes)
  