enthought/pyface — comment on commit 7955400dd123afb43fc444a422de9788f7a26082
File: pyface/ui/qt4/action/action_item.py line 137
By jdmarch:

In a Tasks application under development, using pyside (not pyqt), this throws a TypeError because it is invoked with only 1 (self) parameter. The following "works" though presumably fails to achieve the purpose of the change. It does not suffice simply to change the signature; then the app crashes shortly after self.control is cleared.

def _qt4_on_destroyed(self, control=None):
if control is not None:
self.control = None