cmd/go: Go modules should accept version tags without a leading "v" and without a patch version

[kevinburke]

I tag versions on my projects the same way the Go project does:

• 0.6
• 1.0
• 1.1
• 1.2
• 1.3

etc. These versions are not recognized by the Go module tool. I accidentally pushed a tag to my project that someone committed to a fork of my project ("v1.0.2") and despite being live for under an hour, now this tag has been cached by the Go proxy cache in perpetuity, as the "latest" module tag for the project, the default one you get when you try to install the source code.

Since there's no way to delete the tag from the proxy module cache I'm now in the unfortunate position of needing to rewrite all of the tags for my project to include "v" at the beginning, and also include a patch version ("v1.0.0"). This is really unfortunate. This is why I do not use the proxy module cache myself and instruct everyone at my company not to use it either.

It's odd that I should be forced to do this when Go itself does not include patch versions for some of its version numbers - "go1.16" is a valid version - and does not include a leading "v" when tagging or versioning releases.

[seankhliao]

Duplicate of #32945

[jayconrod]

@kevinburke If it helps, you can push a new version that retracts the accidentally tagged version and itself. Then @latest should resolve to a pseudo-version again (assuming there are no other release versions).

// Tagged accidentally.
retract v1.0.2

// Only contains retractions.
retract v1.0.3