[C++-sig] Re: boost::python and exceptions, seg fault

[Jacques A. Vidrine]

On Thu, Jun 05, 2003 at 11:03:25PM -0400, David Abrahams wrote:
> 
> Please keep this dissussion on the C++-sig rather than emailing me
> personally.

I would be happy to.  For some reason your message to which I was
replying (Message-ID: <uptlt36vd.fsf at boost-consulting.com>) did not
include c++-sig in the headers. [1]

> "Jacques A. Vidrine" <nectar at celabo.org> writes:
[...]
> > but it apparently didn't run the test :-)
> 
> How do you know it didn't run the test?

Sorry, I made a bad assumption.  Double-checking, the test actually
/did/ run.

> > When I actually load and call the exception_translator_ext, the
> > exception is uncaught as in my previous simple example.
> >
> >   % pwd
> >   ~/boost_1_29_0/libs/python/test
> >   % cd bin/exception_translator_ext.so/gcc/debug/runtime-link-dynamic/shared-linkable-true/
> >   % env PYTHONPATH="$PWD" python                                                                            
> >   Python 2.2.2 (#1, Feb 11 2003, 21:28:43)                
> >   [GCC 3.2.2 [FreeBSD] 20030205 (release)] on freebsd5
> >   Type "help", "copyright", "credits" or "license" for more information.
> >   >>> import exception_translator_ext
> >   >>> exception_translator_ext.throw_error()
> >   zsh: 30040 abort (core dumped)  env PYTHONPATH="$PWD" python
> 
> This doesn't prove much.  The point of running the example under bjam
> is that it handles setting up the environment properly.

I guess it means a lot to me.  Like you said, clearly there is
something different in the runtime environment.

After some further investigating, it appears that the `release'
build library (i.e. .../gcc/release/.../libboost_python.so) may be
the culprit.  The `release' library was installed, but the `debug'
library was used in the tests.  The test crashes when run against the
`release' library, but completes successfully when run against the
`debug' library.

My own applications work with the `debug' library.  I'm afraid I don't
know enough about the Boost build system at this time to indicate what
exactly is the difference between the `debug' and `release' built
bits.  If someone could point out where to look for these things, I
would be happy to continue to try to track down the issue.  It seems
likely to be some (over)optimization flag or such that tickles a gcc
bug.

It seems this issue has come up in the c++-sig archives at least two
other times this year, but it has not seemed to be resolved (on the
list).

    http://mail.python.org/pipermail/c++-sig/2003-March/003636.html
    http://mail.python.org/pipermail/c++-sig/2003-January/003152.html

I suspect it can be readily reproduced with gcc 3.2.x, at least.

I wonder if the environment used for testing is not flawed if it does
not exercise the `release' build?

Cheers,
-- 
Jacques Vidrine   . NTT/Verio SME      . FreeBSD UNIX       . Heimdal
nectar at celabo.org . jvidrine at verio.net . nectar at freebsd.org . nectar at kth.se


[1] Although I /do/ see it in the archives now, *shrug*.