This little program

<?php
  list ( $x , $x ) = array ( 1 , 2 );
?>

leads to the following output and a coredump:

[Wed Jan  5 01:26:36 2000]  Script:  'test.php'
---------------------------------------
zend_alloc.c(355) : Block 0x08158168 status:
Beginning:      Overrun (magic=0x5A5A5A5A, expected=0x7312F8DC)
      End:      Unknown
---------------------------------------
Segmentation fault (core dumped)