Method hooks swallow AttributeError

If AttributeError is raised by a Method/Function hook, it is silently swallowed:

class C(Schema):
    f = fields.Method('_bad_serialize')
    def _bad_serialize(self, obj):
        return self._do_something_else(obj)  # raises AttributeError

test_type = namedtuple('test_type', 'f')
C(strict=True).dump(test_type(123))  # returns empty list

This makes finding the bugs harder. I understand the rationale and I guess fixing it might make some code backward incompatible, but is there a way to add at least some warning mode?

[sloria]

I intend to look into solutions for this in marshmallow 3.0

[hanselpaze]

This is super annoying… and should at least come with a way to switch off this behaviour for debugging purposes.