Debugging howto

[Dean Montgomery]

What are some recommended debugging tools for cups on Linux?
I would like to be able to step through the execution of the code, set breakpoints, and read the contents of variables?

I would like to fix a bug in Debian Lenny's CUPS 1.3.8.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=556018
http://www.cups.org/str.php?L3436

Upgrading cups to 1.4 is not an option in Debian Lenny.

By reading through the code i know that the template is not getting the variables passed to it.
templates/jobs-header.tmpl
cgi-bin/ipp-var.c

I've tried several changes to the code and re-compile without success - I need the to be able to step through the code during execution in order to resolve this bug in Debian Lenny.