I'm running the following on Solaris 9 SPARC:

python 2.5
apache 2.2
mod_python 3.3.1
subversion 1.4.4
trac 0.11dev

Trac is a web application that's written in python and is running through apache using mod_python. It also uses the subversion python libraries.

After an undetermined amount of clicks (usually in the order of a minute or two of randomly clicking around) the apache child process dies:

[Sat Jul 21 17:47:27 2007] [error] [client myip] mod_python (pid=15138, interpreter='my.site.com', phase='PythonHandler', handler='trac.web.modpython_frontend'): Application error, referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] ServerName: 'my.site.com', referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] DocumentRoot: '/path/to/docroot', referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] URI: '/trac/', referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] Location: '/trac', referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] Directory: None, referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] Filename: '/path/to/docroot', referer: http://my.site.com/
[Sat Jul 21 17:47:27 2007] [error] [client myip] PathInfo: '/trac/', referer: http://my.site.com/

It's dumped a core file. Examining that with gdb shows a Bus error here:

Core was generated by `/usr/local/sbin/httpd -DLocalConfig -k start'.
Program terminated with signal 10, Bus error.
#0  PyObject_Malloc (nbytes=16) at Objects/obmalloc.c:747
747                             if ((pool->freeblock = *(block **)bp) != NULL) {
(gdb) l
742                              * Pick up the head block of its free list.
743                              */
744                             ++pool->ref.count;
745                             bp = pool->freeblock;
746                             assert(bp != NULL);
747                             if ((pool->freeblock = *(block **)bp) != NULL) {
748                                     UNLOCK();
749                                     return (void *)bp;
750                             }
751                             /*
(gdb) 

Full gdb output is attached.

I've tried disabling pymalloc when building python, but the problem just moves elsewhere. However, with pymalloc enabled it's consistently on this line.

Do you have advice on how to debug this further?