Really surprised nobody has mentioned gopkg.in.
gopkg.in
is a service that provides a wrapper (redirect) that lets you express versions as repo urls, without actually creating repos. E.g. gopkg.in/yaml.v1
vs gopkg.in/yaml.v2
, even though they both live at https://github.com/go-yaml/yaml
This isn't perfect if the author is not following proper versioning practices (by incrementing the version number when breaking backwards compatibility), but it does work with branches and tags.