Unable to call QtCore.QObject.__new__ in Python 2.7

We have a singleton metaclass based on type(QtCore.QObject) in the __call__
method we create a new instance of the class and return it

def __call__(self, *args, **kwargs):
    instance = self.__new__(self, *args, **kwargs)
    instance.__init__(*args, **kwargs)
    return instance

or, if you want the one-liner version:

QtCore.QObject.__new__(QtCore.QObject, "", (), {})

the error obtained running this code on Python2 is:

TypeError: PySide2.QtCore.QObject.__new__(PySide2.QtCore.QObject) is not safe, use object.__new__()

the same one-liner works on Python3, I think it is related to PYSIDE-816 and heap types.