Debugging PHP can really be a pain in the ....
I have quite some PHP scripts partly copied from other sources and some developedmyself and when they finally worked: DO NOT TOUCH! anymore.
Well, I came to a point I did not have many options but to alter one of these NO TOUCH screens.
Of course after making the changes the script did not work anymore
Lucky for me I had learned a language called REBOL. I decided to rewrite my PHP code like it were a REBOL script using the REBOL indentation and breaking the script using what I had learned.
And guess what? Breaking up the script like this made it a whole lot more readable and almost by magic the errors I made showed up because there were things missing I expected there to be, like in the REBOL script there would be.
This experience made me cross out PHP experience from my resume, because the standards used everywhere in the industry are those of the unreadable undebuggable scripts I swore I never wanted to debug anymore.
Hope this helps a tiny bit,
Arnold