Using latest py3k SVN on MacOSX 10.5.2 :

[~/Sources/py3k/Lib/test]> ../../python regrtest.py test_urllib.py 
test_urllib
zsh: bus error  ../../python regrtest.py test_urllib.py

Backtrace:

#0  _CallProc (pProc=0x904e95f0 <CFStringCreateWithCString>, 
argtuple=0x5e7bc0, flags=4353, argtypes=0x0, restype=0x2637b0, 
checker=0x0) at 
/Users/cartman/Sources/py3k/Modules/_ctypes/callproc.c:984
#1  0x00662352 in CFuncPtr_call (self=0x5c9738, inargs=0x5e7bc0, 
kwds=0x0) at /Users/cartman/Sources/py3k/Modules/_ctypes/_ctypes.c:3767
#2  0x00008229 in PyObject_Call (func=0x5c9738, arg=0x5e7bc0, kw=0x0) at 
Objects/abstract.c:2184
#3  0x0009e9f4 in <unknown function> [inlined] () at :0
#4  0x0009e9f4 in PyEval_EvalFrameEx (f=0x2615e0, throwflag=0) at 
Python/ceval.c:0
#5  0x0009ffc8 in PyEval_EvalFrameEx (f=0x23f6d0, throwflag=0) at 
Python/ceval.c:3536
#6  0x0009ffc8 in PyEval_EvalFrameEx (f=0x260d70, throwflag=0) at 
Python/ceval.c:3536
#7  0x000a1133 in PyEval_EvalCodeEx (co=0x3cfcc8, globals=0x3c60c0, 
locals=0x0, args=0x5eb6dc, argcount=1, kws=0x2576d0, kwcount=0, 
defs=0x54d9bc, defcount=1, kwdefs=0x0, closure=0x0) at 
Python/ceval.c:2743
#8  0x0002b055 in function_call (func=0x54cd68, arg=0x5eb6d0, 
kw=0x5ecb70) at Objects/funcobject.c:628
#9  0x00008229 in PyObject_Call (func=0x54cd68, arg=0x5eb6d0, 
kw=0x5ecb70) at Objects/abstract.c:2184
#10 0x0009d418 in PyEval_EvalFrameEx (f=0x260c00, throwflag=0) at 
Python/ceval.c:3749
#11 0x000a1133 in PyEval_EvalCodeEx (co=0x3d53c8, globals=0x3c60c0, 
locals=0x0, args=0x5eb6bc, argcount=1, kws=0x0, kwcount=0, defs=0x0, 
defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#12 0x0002b055 in function_call (func=0x5321e0, arg=0x5eb6b0, kw=0x0) at 
Objects/funcobject.c:628
#13 0x00008229 in PyObject_Call (func=0x5321e0, arg=0x5eb6b0, kw=0x0) at 
Objects/abstract.c:2184
#14 0x0001715e in method_call (func=0x5321e0, arg=0x1ac030, kw=0x0) at 
Objects/classobject.c:323
#15 0x00008229 in PyObject_Call (func=0x5230a8, arg=0x1ac030, kw=0x0) at 
Objects/abstract.c:2184
#16 0x000579c7 in slot_tp_init (self=0x0, args=0x1ac030, kwds=0x0) at 
Objects/typeobject.c:5187
#17 0x00053be2 in type_call (type=0x24f8f0, args=0x1ac030, kwds=0x0) at 
Objects/typeobject.c:651
#18 0x00008229 in PyObject_Call (func=0x24f8f0, arg=0x1ac030, kw=0x0) at 
Objects/abstract.c:2184
#19 0x0009e9f4 in <unknown function> [inlined] () at :0
#20 0x0009e9f4 in PyEval_EvalFrameEx (f=0x260a90, throwflag=0) at 
Python/ceval.c:0
#21 0x000a1133 in PyEval_EvalCodeEx (co=0x3cfb60, globals=0x3c60c0, 
locals=0x0, args=0x2608e4, argcount=1, kws=0x2608e8, kwcount=0, 
defs=0x3cbeec, defcount=2, kwdefs=0x0, closure=0x0) at 
Python/ceval.c:2743
#22 0x0009f874 in <unknown function> [inlined] () at :0
#23 0x0009f874 in PyEval_EvalFrameEx (f=0x2607a0, throwflag=0) at 
Python/ceval.c:0
#24 0x0009ffc8 in PyEval_EvalFrameEx (f=0x25f3d0, throwflag=0) at 
Python/ceval.c:3536
#25 0x000a1133 in PyEval_EvalCodeEx (co=0x538848, globals=0x5330c0, 
locals=0x0, args=0x5de67c, argcount=2, kws=0x258880, kwcount=0, 
defs=0x5b569c, defcount=1, kwdefs=0x0, closure=0x0) at 
Python/ceval.c:2743
#26 0x0002b055 in function_call (func=0x5b68e8, arg=0x5de670, 
kw=0x5ec930) at Objects/funcobject.c:628
#27 0x00008229 in PyObject_Call (func=0x5b68e8, arg=0x5de670, 
kw=0x5ec930) at Objects/abstract.c:2184
#28 0x0009d418 in PyEval_EvalFrameEx (f=0x25f260, throwflag=0) at 
Python/ceval.c:3749
#29 0x000a1133 in PyEval_EvalCodeEx (co=0x538890, globals=0x5330c0, 
locals=0x0, args=0x5dedfc, argcount=2, kws=0x0, kwcount=0, defs=0x0, 
defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#30 0x0002b055 in function_call (func=0x5b6930, arg=0x5dedf0, kw=0x0) at 
Objects/funcobject.c:628
#31 0x00008229 in PyObject_Call (func=0x5b6930, arg=0x5dedf0, kw=0x0) at 
Objects/abstract.c:2184
#32 0x0001715e in method_call (func=0x5b6930, arg=0x5eb650, kw=0x0) at 
Objects/classobject.c:323
#33 0x00008229 in PyObject_Call (func=0x523198, arg=0x5eb650, kw=0x0) at 
Objects/abstract.c:2184
#34 0x00057d97 in slot_tp_call (self=0x0, args=0x5eb650, kwds=0x0) at 
Objects/typeobject.c:4960
#35 0x00008229 in PyObject_Call (func=0x5e3e50, arg=0x5eb650, kw=0x0) at 
Objects/abstract.c:2184
#36 0x0009e9f4 in <unknown function> [inlined] () at :0
#37 0x0009e9f4 in PyEval_EvalFrameEx (f=0x25f0f0, throwflag=0) at 
Python/ceval.c:0
#38 0x000a1133 in PyEval_EvalCodeEx (co=0x538f50, globals=0x5330c0, 
locals=0x0, args=0x5de6a4, argcount=2, kws=0x258870, kwcount=0, 
defs=0x0, defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#39 0x0002b055 in function_call (func=0x5b6e88, arg=0x5de698, 
kw=0x5ec8a0) at Objects/funcobject.c:628
#40 0x00008229 in PyObject_Call (func=0x5b6e88, arg=0x5de698, 
kw=0x5ec8a0) at Objects/abstract.c:2184
#41 0x0009d418 in PyEval_EvalFrameEx (f=0x25ef80, throwflag=0) at 
Python/ceval.c:3749
#42 0x000a1133 in PyEval_EvalCodeEx (co=0x538f98, globals=0x5330c0, 
locals=0x0, args=0x5de744, argcount=2, kws=0x0, kwcount=0, defs=0x0, 
defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#43 0x0002b055 in function_call (func=0x5b6ed0, arg=0x5de738, kw=0x0) at 
Objects/funcobject.c:628
#44 0x00008229 in PyObject_Call (func=0x5b6ed0, arg=0x5de738, kw=0x0) at 
Objects/abstract.c:2184
#45 0x0001715e in method_call (func=0x5b6ed0, arg=0x5eb5b0, kw=0x0) at 
Objects/classobject.c:323
#46 0x00008229 in PyObject_Call (func=0x5230d0, arg=0x5eb5b0, kw=0x0) at 
Objects/abstract.c:2184
#47 0x00057d97 in slot_tp_call (self=0x0, args=0x5eb5b0, kwds=0x0) at 
Objects/typeobject.c:4960
#48 0x00008229 in PyObject_Call (func=0x5e3eb0, arg=0x5eb5b0, kw=0x0) at 
Objects/abstract.c:2184
#49 0x0009e9f4 in <unknown function> [inlined] () at :0
#50 0x0009e9f4 in PyEval_EvalFrameEx (f=0x25ee10, throwflag=0) at 
Python/ceval.c:0
#51 0x000a1133 in PyEval_EvalCodeEx (co=0x538f50, globals=0x5330c0, 
locals=0x0, args=0x5de5b4, argcount=2, kws=0x254b40, kwcount=0, 
defs=0x0, defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#52 0x0002b055 in function_call (func=0x5b6e88, arg=0x5de5a8, 
kw=0x5ec810) at Objects/funcobject.c:628
#53 0x00008229 in PyObject_Call (func=0x5b6e88, arg=0x5de5a8, 
kw=0x5ec810) at Objects/abstract.c:2184
#54 0x0009d418 in PyEval_EvalFrameEx (f=0x25eca0, throwflag=0) at 
Python/ceval.c:3749
#55 0x000a1133 in PyEval_EvalCodeEx (co=0x538f98, globals=0x5330c0, 
locals=0x0, args=0x53a924, argcount=2, kws=0x0, kwcount=0, defs=0x0, 
defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#56 0x0002b055 in function_call (func=0x5b6ed0, arg=0x53a918, kw=0x0) at 
Objects/funcobject.c:628
#57 0x00008229 in PyObject_Call (func=0x5b6ed0, arg=0x53a918, kw=0x0) at 
Objects/abstract.c:2184
#58 0x0001715e in method_call (func=0x5b6ed0, arg=0x5eb450, kw=0x0) at 
Objects/classobject.c:323
#59 0x00008229 in PyObject_Call (func=0x578e18, arg=0x5eb450, kw=0x0) at 
Objects/abstract.c:2184
#60 0x00057d97 in slot_tp_call (self=0x0, args=0x5eb450, kwds=0x0) at 
Objects/typeobject.c:4960
#61 0x00008229 in PyObject_Call (func=0x53f8f0, arg=0x5eb450, kw=0x0) at 
Objects/abstract.c:2184
#62 0x0009e9f4 in <unknown function> [inlined] () at :0
#63 0x0009e9f4 in PyEval_EvalFrameEx (f=0x25e560, throwflag=0) at 
Python/ceval.c:0
#64 0x0009ffc8 in PyEval_EvalFrameEx (f=0x25e120, throwflag=0) at 
Python/ceval.c:3536
#65 0x0009ffc8 in PyEval_EvalFrameEx (f=0x25b070, throwflag=0) at 
Python/ceval.c:3536
#66 0x000a1133 in PyEval_EvalCodeEx (co=0x5bca40, globals=0x533c90, 
locals=0x0, args=0x25074c, argcount=7, kws=0x250768, kwcount=0, 
defs=0x0, defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#67 0x0009f874 in <unknown function> [inlined] () at :0
#68 0x0009f874 in PyEval_EvalFrameEx (f=0x250610, throwflag=0) at 
Python/ceval.c:0
#69 0x0009ffc8 in PyEval_EvalFrameEx (f=0x233530, throwflag=0) at 
Python/ceval.c:3536
#70 0x000a1133 in PyEval_EvalCodeEx (co=0x3cfa88, globals=0x1d50c0, 
locals=0x1d50c0, args=0x0, argcount=0, kws=0x0, kwcount=0, defs=0x0, 
defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:2743
#71 0x000a12ef in PyEval_EvalCode (co=0x0, globals=0x0, locals=0x0) at 
Python/ceval.c:500
#72 0x000c7691 in <unknown function> [inlined] () at :0
#73 0x000c7691 in PyRun_FileExFlags (fp=0xa0670de0, filename=0xbffff2dc 
"test_urllib.py", start=257, globals=0x1d50c0, locals=0x1d50c0, 
closeit=1, flags=0xbffff73c) at Python/pythonrun.c:0
#74 0x000c7b23 in PyRun_SimpleFileExFlags (fp=<value temporarily 
unavailable, due to optimizations>, filename=0xbffff2dc 
"test_urllib.py", closeit=1, flags=0xbffff73c) at 
Python/pythonrun.c:1040
#75 0x000d4da9 in Py_Main (argc=2, argv=0x2000f0) at Modules/main.c:592
#76 0x000024c0 in main (argc=2, argv=0xbffff808) at python.c:57

Should be fixed in r63448.