Comment 3 for bug 392521

Confirmed on Ubuntu 9.04 Jaunty amd64.

Steps to reproduce (and capture a backtrace) are:

# Ensure we dump core
ulimit -c 2000000
# Delete any pre-existing core file
rm core
# Create a command input file for use by gdb
echo bt >/tmp/bt
# Create a trivial PHP script
echo -e "<?php\n?>\n" >/tmp/a.php
# Check it 100 times
for i in `seq 1 100` ; do php -l /tmp/a.php >/dev/null; done
# Run GDB to capture the backtrace
gdb -batch -x /tmp/bt `which php` core
# Clean up temp files
rm core /tmp/bt /tmp/a.php

Backtrace attached. It might be worth trying it with a debug version of PHP
if this backtrace is insufficient.