> Why are you not able to easily version git dependencies? Go's solution to this problem is to tell you to create an entirely new git repository for each major version. Really? If they didn't want to go full blown dependency versioning with something like CocoaPods, they could at least let you specify a git branch or tag.
Take a look at gopkg.in[1]. This is a service that makes branches in other repositories go-gettable. Eg. go getting gopkg.in/foo/bar/v5 will download branch v5 from github.com/foo/bar. This seems to me to be a way of dealing reasonaly well with the issue -- the go get tool itself doesn't need to understand anything at all here.