go/build: Import() fails for packages using modules and version greater than 1

[joshuarubin]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

tip

Does this issue reproduce with the latest release?

n/a

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

darwin/amd64

What did you do?

build.Import() returns an error when trying to load a package from a module with version greater than 1.

cannot find package "github.com/foo/bar/v2" in any of:
...

I got to this indirectly through this:

import (
	"go/ast"
	"go/importer"
	"go/types"
)

func foo() {
	cfg := types.Config{
		Importer: importer.For("source", nil),
	}
	_, err := cfg.Check(...)
}

Where cfg.Check returned:

could not import github.com/foo/bar/v2 (cannot find package "github.com/foo/bar/v2" in any of:
...

What did you expect to see?

The go/* packages in the stdlib work the same way as vgo with the ability to load packages from versioned modules.

What did you see instead?

The errors listed above

[bcmills]

CC: @alandonovan @ianthehat @rsc

[rsc]

The answer is to use golang.org/x/tools/go/packages, under development now. If you find any problems using that package, please file new issues against it. Thanks very much.

[rsc]

I take it back - that's the long term answer but we can provide a short-term answer. I reopened this as #26504.