: [Python-Dev] RE: Painful death in debug build

[Guido van Rossum]

So the problem is that one size calculation rounds up to multiples of
a pointer size and the other doesn't; unfortunately the one that
doesn't gets passed to malloc.  The reason for the rounding up --a
recent addition-- is that when you derive a subclass from tuple,
string or long, the __dict__ of the subclass instance (and its weakref
list head) are allocated after the variable-length portion of the
instance.  I propose to fix the other size calculation to also round
up.  I'll leave it to you to fix this, since you've almost nailed this
already (and since I'm not feeling so great right now).

--Guido van Rossum (home page: http://www.python.org/~guido/)