import pdb

class foo:
    def __init__(self):
        # crash on pdb commands:
        #   args
        #   python3: display self
        # silently fail on pdb commands: p self, pp self
        pdb.set_trace()
        foo.bar = "hello"
    def __repr__(self):
        return foo.bar

class C(object):
    def __new__(cls, *args, **kwds):
        # python3: crash on pdb commands: step followed by retval
        # python2: crash on pdb commands: step, return
        pdb.set_trace()
        return object.__new__(cls)

    def __init__(self, value):
        self.value = value

    def __repr__(self):
        return str(self.value)

# Hit 'continue' at the first pdb prompt to test class C.
foo()
C(123)