_pickle.c: 补丁包还存在一些问题，等正式版发布再看如何，临时这样解决。
	http://bugs.python.org/issue22676
	getattribute(PyObject *obj, PyObject *name, int allow_qualname) {
                PyErr_Format(PyExc_AttributeError,
                             "Can't get attribute %s on XXX", name);