[Stackless] http://www.stackless.com/pipermail/stackless/2007-April/000142.html

[Richard Tew]

On Thu, Apr 12, 2012 at 10:24 PM, Kristján Valur Jónsson
<kristjan at ccpgames.com> wrote:
> Aha, maybe the issue is with b, because currently stackless may be assuming that all PyHeapTypeObjects have the stackless extension, even though they don't have the flag.
> Fixing this may be sufficient, then.  Let me go in and have a look at the problem.

Yes, SIP does the following:

struct X {
    ...
    PyHeapTypeObject y;
    ...
}

And when compiled against cpython, and used against Stackless, the
expectation of a longer y could result in Stackless clobbering
trailing fields of X.  If you have a way to fix what you describe
above, this should also be covered.

Cheers,
Richard.