[icebraining]

You're right, but in my experience, even non-novel software features can be hard to accurately estimate, especially due to yak shaving.

Last week I was asked to add a button to a form that calls a service endpoint, same as the other five buttons that I already implemented, and which took me around 30m, so this should be easy, right?

Except during testing the service throws this weird error that makes no sense, and so I have to start debugging, by tracing the code and possibly looking at the network traffic. I find that the library I'm using is sending a weird request, which with a bit of Googling tells me it's a known bug, and which has a patch, but that doesn't apply to our deployed version of the library.

So now I'm two hours into this half-hour task, and I'm trying to decide whether I should spend the time to backport this fix and re-test all the code using the library, or implement some kludge that solves this problem but increases the effort of anyone in the future that touches this code.