gnode and introspection

[Andrea Zagli <azagli libero it>]

i have a library (the same as thet thread before) that have a method  
that returns a gnode

but when it is introspected by g-ir-scanner i got

Warning: Confi: confi_get_tree: return value: Invalid non-constant  
return of bare structure or union; register as boxed type or (skip)

how must i annotate/declare a return value of type gnode?

thanks in advance