They did get one benefit from this choice: > the version number alone should be enough to unambiguously differentiate between APIv1 and APIv2. ...which is how

They did get one benefit from this choice: > the version number alone should be enough to unambiguously differentiate between APIv1 and APIv2. ...which is how version numbers normally work. They've made a big breaking change in a 1.X release, so it isn't semver, but that isn't the end of the world. It works around having to put the major version number in the import path too, so really it works like most other non-Go, non-semver, projects.