The "Debugging 101" thread contains 60 snippets of advice, or commentaries thereupon, and has been viewed over 114K times since 2003.
However, ... 2003.
Perhaps we should review the advice there and create a new thread that reflects more adequately the knowledge gained over the last 14 years, the parts of PHP that are no longer to be used (deprecated, bad practice, if any), the new technologies available inside the language and its environment, and new tools for debugging?
AFAIK, it's not possible for us to edit it, unless we're mods maybe (?) Of course, some of us are. I defer such decisions to my betters ... but I thought it might be worth bringing up.