I commented on Stack Overflow, and someone replied "that's too fine" to me.
What does this sentence mean?
It appears like they were trying to say "that is fine too" or, in other words, "that is also an acceptable way of doing it".
If they really meant "that's too fine" (which I really doubt), it would mean something like:
That is just nonsensical. It is most likely a typo or a non-native English speaker. Looking at their other answers/comments, it would appear they are from a non-Enligh speaking country. See this other example:
where the brackets are needed
That is out of order, and should be: "where are the brackets needed?" That isn't the kind of mistake a lazy native speaker would make.
In a very different context, it could be understood as a compliment. But that is only for urban slang, and it only refers to attractiveness of another person (or body part).
That booty is too fine.
I feel embarrassed just typing that, but I figured you should know it could be said. That is definitely not what that user was trying to say though. That's just some trivia.
In an engineering discussion, "that's too fine" would refer to something like the thread pitch of a screw or a surface finish which can be defined as too fine for the purpose and thus unnecessarily expensive. In the context of that original post, I would too say he/she mean "that's also fine".