[Pyobjc-dev] debugging pyobjc

[Michael H. <mw...@py...>]

I'm vaguely trying to track down a bug in recent versions of pygame on
MacOS X, which now uses PyObjC.  So, after much wailing and gnashing
of teeth (see pythonmac-sig) I have a debugging framework install of
Python, and seem to have built pyobjc against it.

1) PyObjC's setup.py seems to unconditionally pass -O3 to the
   compiler.  This is, um, contrary to the spirit of a debug build.
   What's wrong with the value of CFLAGS you get by default (from
   $(prefix)/lib/python$(VERSION)/config/Makefile)?

2) Stuff like this isn't encouraging:

[mwh@pc150 mwh]$ /Library/Frameworks/DbgPython.framework/Versions/Current/bin/python2.3 
Python 2.3.3 (#1, Jan 22 2004, 14:18:14) 
[GCC 3.3 20030304 (Apple Computer, Inc. build 1493)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import Foundation
[54592 refs]
>>> 
[54592 refs]
Debug memory block at address p=0x44ead0:
    40834 bytes originally requested
    The 4 pad bytes at p-4 are not all FORBIDDENBYTE (0xfb):
        at p-4: 0x00 *** OUCH
        at p-3: 0x44 *** OUCH
        at p-2: 0x00 *** OUCH
        at p-1: 0x01 *** OUCH
    Because memory is corrupted at the start, the count of bytes requested
       may be bogus, and checking the trailing pad bytes may segfault.
    The 4 pad bytes at tail=0x458a52 are not all FORBIDDENBYTE (0xfb):
        at tail+0: 0x00 *** OUCH
        at tail+1: 0x20 *** OUCH
        at tail+2: 0x7c *** OUCH
        at tail+3: 0x08 *** OUCH
    The block was made by call #44482497 to debug malloc/realloc.
    Data at p: 40 40 3a 40 00 00 00 00 ... 03 a6 bb c1 ff f8 4e 80
Fatal Python error: bad leading pad byte

Am I in new territory here?

Cheers,
mwh

-- 
   This proposal, if accepted, will probably mean a heck of a lot of
   work for somebody.  But since I don't want it accepted, I don't
   care.                                   -- Laura Creighton, PEP 666