debugging

Finding out when something went wrong in a running world.

The job this skill covers is not "what is the current value" — the current value is downstream of the moment that matters. It is: attach an instrument to running code, keep working, and be told the instant the thing happens.

It exists because the reflex it replaces does not work. Running something, waiting, and taking a capture aims at a moment you cannot see: seconds pass between the call and the frame, and adding a wait only moves the guess. Polling is the same guess with more steps.

Covers: probing a function call, a source line, or a value; using a condition to name the moment rather than every step toward it; reading the state a value was taken in before trusting the value; and cancelling what you armed.

The trap it spends the most words on is the expensive one — a right value read in the wrong world, where the match already ended or the scene already swapped, nothing announced it, and every number afterwards means something else.