how to debug why a building won't pull fluid

[Mithaldu]

I'm in the situation that i just added a mod (specifically pyal) to a running game (with the rest of the pymods).

Suddenly a specific building that uses 165° steam, which is connected to a pipe filled with 165° steam fails to take steam from the pre-existing pipe.

This is clearly a bug.

On a very general level:

How do i get extra information from the game as to why the already connected pipe's steam is now incompatible? Which debug flags get me this information?