Go version

59275e2

What operating system and processor architecture are you using (go env)?

N/A

What did you do?

Read https://go.dev/ref/mod#versions.

What did you expect to see?

A description of the actual behavior of the go command.¹

Concretely:

• go get accepts versions with +metadata suffixes, and will accept such a tag as the base for a pseudo-version.
• However, because Semantic Version specifies that +metadata has no effect on version precedence, go commands convert such versions to unambiguous, totally-ordered pseudo-versions for the purpose of version selection, and those pseudo-versions are what are ultimately written to the go.mod file.

¹https://cs.opensource.google/go/go/+/master:src/cmd/go/internal/modfetch/coderepo.go;l=586-596;drc=46ea4ab5cb87e9e5d443029f5f1a4bba012804d3

What did you see instead?

(emphasis added)

The build metadata suffix is ignored for the purpose of comparing versions. Tags with build metadata are ignored in version control repositories, but build metadata is preserved in versions specified in go.mod files. The suffix +incompatible denotes a version released before migrating to modules version major version 2 or later (see Compatibility with non-module repositories).