Once you've a running php installation on your Ubuntu 10.4 you may want to add xdebug to it.
It's simple as pie with one pitfall in it.
apt-get install php5-xdebug
After that you have to add these lines to your php.ini
display_error = On
html_errors = On
xdebug.profiler_enable = 1
xdebug.profiler_output_name = cachegrind.out.%R
xdebug.profiler_output_dir = "/tmp/"
to get it work. Restart your HTTP-daemon to make changes take effect.
And check out
apt-get install kcachegrind
to handle the xdebug logs in /tmp
Did it work for you? Just drop a comment.