What the author may be missing in the vgo command is that v1 can reference v2 because they are name differently. That, along with alias, provides a powerful way

What the author may be missing in the vgo command is that v1 can reference v2 because they are name differently. That, along with alias, provides a powerful way to have a single unit of of code that is represented in two ways. See https://research.swtch.com/vgo-import https://research.swtch.com/vgo-import under "Automatic API Updates". Also, their point about not asking developers to choose the semver just like you don't ask developers to write diffs is valid. This is exactly what rsc proposes the "(v)go release" command do in https://research.swtch.com/vgo-cmd https://research.swtch.com/vgo-cmd under "Preparing New Versions (go release)".