Second, I don't know anything about the debugging of the Euler characteristic, but I suggest that the issue here is better characterized as taking decades to discover the correct representation. Sort of like Edison finding 1000 lightbulb ideas that didn't work, before finding one that did. (Don't take that analogy too far... I'm not suggesting that physical things are discovered in the same way that mathematical things are discovered. (But I'm also not suggesting that they are not.))