stepping away for a bit helps, but like you said, what needs to be done is to patiently observe, often step-by-step, what is *actually* happening. that usually helps reveal that what i assumed was happening, was not.

i’d add that this is especially true if working by oneself. if i can get someone else to look at it, they essentially will do the same thing, just not assume what i have been taking for granted all along. i’ve also found in those conversations that as i describe what it should do, to someone who is fresh to the problem, and walk through the code with them .. that sometimes that brings those assumptions to light too.