(gobject:define-gflags "GtkBuilderClosureFlags" builder-closure-flags
  (:export t
   :type-initializer "gtk_builder_closure_flags_get_type")
  (:swapped #.(ash 1 0)))  

:swapped

The closure should be created swapped.

The list of flags that can be passed to the gtk:builder-create-closure function. New values may be added in the future for new features, so external implementations of the gtk:builder-scope interface should test the flags for unknown values and raise an error when they encounter one.