[Python-Dev] test_subprocess and sparc buildbots

[Alexandre Vassalotti]

On Tue, Dec 30, 2008 at 10:41 PM, Daniel (ajax) Diniz <ajaksu at gmail.com> wrote:
> A reliable way to get that in a --with-pydebug build seems to be:
>
> ~/py3k$ ./python -c "import locale; locale.format_string(1,1)"
> * ob
> object  : <refcnt 0 at 0x825c76c>
> type    : tuple
> refcount: 0
> address : 0x825c76c
> * op->_ob_prev->_ob_next
> NULL
> * op->_ob_next->_ob_prev
> object  : <refcnt 0 at 0x825c76c>
> type    : tuple
> refcount: 0
> address : 0x825c76c
> Fatal Python error: UNREF invalid object
> TypeError: expected string or buffer
> Aborted
>

Nice catch! I reduced your example to: "import _sre;  _sre.compile(0,
0, [])". And, it doesn't seem to be an input validation problem with
_sre. From what I saw, it's actually a bug in Py_TRACE_REFS's code.
Now, it's getting interesting!

It seems something is breaking the refchain. However, I don't know
what is causing the problem exactly.

> Found using Fusil in a very quick run on top of:
> Python 3.1a0 (py3k:68055M, Dec 31 2008, 01:34:52)
> [GCC 4.2.4 (Ubuntu 4.2.4-1ubuntu3)] on linux2
>
> So kudos to Victor again :)
>

Could share the details on how you used Fusil to find another crasher?
It sounds like a useful tool.

Thanks!

-- Alexandre