> Sorry if this has been posted already, I didn't quite know how to
> phrase the problem, hence the weird title of this email.

> In the following example (using Cython 0.14.1):

> # ------------------------ #
> cdef class MyList(list):
>    def foo(self):
>        print "foo"

> cdef class Bar(object):
>    cdef MyList _attributes

>    def __init__(self, list attributes=None):
>        self.attributes = attributes if attributes is not None else []

>    property attributes:
>        def __get__(self):
>            return self._attributes

>        def __set__(self, list attributes not None):
>            self._attributes = attributes

>    cdef int _test(self):
>        self._attributes.append('foo')
> # ------------------------ #

> I'm getting th following error:

> t.c: In function ‘__pyx_f_5hello_3Bar__test’:
> t.c:1148:7: warning: comparison of distinct pointer types lacks a cast
> t.c:1155:56: error: ‘struct __pyx_obj_5hello_MyList’ has no member named ‘None’

> However, if I declare list as an explicit extern type:

> cdef extern from "listobject.h":
>    ctypedef class __builtin__.list [object PyListObject]:
>        pass

> It works. Am I doing something wrong here or is this a bug?

>> This is a bug. However, note that the cython builtin "list" means
>> exactly a list (no subclasses allowed), otherwise we can't safely
>> optimize it (or, at least, we'd have to re-work our optimizations to
>> include dispatches to generic code, in which case there's little
>> benefit to typing it something other than "object."

> Ok, thanks for the explanation! Is there a ticket created for this?