While investigating goup as a potential addition to our CI, I noticed that it uses src-d/go-git to discover available versions. As I was contemplating implementing something similar if I hadn't found goup, I was curious about this repository, but when I went to it, there was a notice at the top of its README saying that development had been moved to go-git/go-git. I would advise that goup should be updated to use the new go-git/go-git library.