People already do everything you said. It's pretty easy to spot. Just look for a bunch of forked projects with no commits by the person in question, a high ratio of forked to original projects, etc.

The biggest giveaway is that there are no projects which are just for fun.

Incidentally, I've observed that the "just for fun" projects is a good trick for identifying a serious economist as well. A real economist Tyler Cowen obsesses over the economics of finding good restaurants and whatever else tickles his fancy, whereas a pretender like Krugman is all serious policy issues (both examples of economists who's policy I tend to disagree with).