free variable 'self' referenced before assignment in enclosing scope
When select in the reference field:
File "/home/resteve/projectes/tryton/tryton/gui/window/view_form/view/form_gtk/reference.py", line 22, in
child.connect('focus-out-event', lambda *a: self._focus_out())
NameError: free variable 'self' referenced before assignment in enclosing scope
GTK 5.7