cmd/doc: `go doc <Symbol>` shows "." as package import path

[hyangah]

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

$ go version
go version devel go1.21-4dae3bbe0e Tue Jun 6 20:24:31 2023 +0000 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What did you do?

Ran go doc <symbol>

project/mod/modfile$ go doc AutoQuote
package modfile // import "."
...

See // import ".".
Compare it with the package doc mode output.

project/mod/modfile$ go doc
package modfile // import "golang.org/x/mod/modfile"
...

What did you expect to see?

Current package's import path.

What did you see instead?

Always // import ".".

[prattmic]

I think the "." comes from https://cs.opensource.google/go/go/+/refs/heads/master:src/cmd/doc/main.go;l=266;drc=ee46f0b5084461978432aa20df003ac52500b0f0, but it isn't clear to me if this is a bug in cmd/doc or go/build.

cc @griesemer @robpike @mvdan @bcmills

[prattmic]

Oops, I misread https://dev.golang.org/owners, that should be cc @rsc for go/build, not @griesemer.