You know it, you build a new extension or a new feature and suddenly an unknown error comes your way. Strangely enough, the Google search doesn't help either.
Now you have to search yourself, but what is the best way to proceed.
Personally, I usually go directly to the core of the system and place the following in front of the error
This way, all methods executed before are presented to me with arguments. Of course I prefer the variant with Xdebug which gives you even more possibilities, but if you are limited in this, this is a nice and fast method to find the error 🙂.