> See unintelligible error from stuff that used to work and now it doesn't
> Ask colleagues if they ever met the error
> Fucktard colleague says "try using the debugger, if you run the code line by line you may probably understand what's wrong"

Dear Fucktard, I've been writing code for 7 years now, you can safely assume I know how to use a debugger if need be.
The thing: when I ask "have you ever met this error" I'm asking if you actually know what's going on, BEFORE diving in a 3 hours long debugging session of code written 6 years ago by people who have left the company in the meantime.

You don't always have to say something. Sometimes it happens: you may not have anything clever to add, and a simple "I'm sorry I don't know" is perfectly fine.