[Zope-dev] Core Dump (Zope 2.7, Python 2.3.3, FreeBSD 4.5)

[Jeffrey P Shell]

I've been experiencing the most peculiar core dump under Zope 2.7.  
It's on a web application we only decided to revive late last week, so 
it was never tested under earlier beta/RC conditions.

The core dump occurs when visiting manage_main on a particular folder.  
The contents of this folder are basically just Python Scripts, Page 
Templates, and a few DTML Methods (including standard_error_message).

I can get manage_main to render in zopectl debug (using 
Testing.make_request to make enough of a REQUEST object for it to 
render with).  And I can read everything in that particular folder with 
zopectl debug.  I used this to experiment with moving items around 
between folders - including moving all of the templates/scripts into 
their own folder outside of the web application.  It still core dumps.  
At one point, I thought I had narrowed it down to a particular template 
(although the reasons for why it would be this template elude me) by 
doing some interactive Python work [I had written some helper 
'move_object' and 'copy_object' functions a while back, and used them 
to move items between a pair of folders and then seeing which one Zope 
would crash on].

I got the contents of the template out using ``zopectl debug``, and 
recreated the template by hand, now that I could actually get into the 
target folder.  It worked for a brief moment, but so did the source 
folder, which now had this one particular template remaining.

I tried various imports and exports of the web application, including 
using one that was known to still be working off of a production server 
(Zope 2.6.1, Python 2.1).  I even tried copying the contents 
(individually) of the folder - completely removing them from original 
context.  It still core dumps.  (Before I tried imports and exports, it 
was running in a Data.fs that had been copied from a Zope 2.6.1 
instance to 2.7.  Python Scripts were recompiled)

Finally, I thought it might be a Python 2.3.3/FreeBSD issue (like there 
were issues with default stack size on Python 2.1.x and FreeBSD).  This 
Python 2.3.3 had been built from source just last week, on the day I 
installed Zope 2.7 final on our development server.  So I downloaded 
Zope 2.6.4 and ran that with Python 2.3.3, importing the problematic 
export.  I could list the contents of this particular folder just fine. 
  The import had Python 2.1 compiled scripts, so I recompiled them and 
exported it again just to see if that was causing strange issues - but 
when brought into Zope 2.7, the core dump still happens.

The folder in question is not terribly large - when I extracted the 
scripts/templates manually into a new folder, I think it has about 41 
items in it.

What should I do next?  Should I familiarize myself with gdb and 
inspect the core?  What are some things I could look for if that's the 
next step?