cmd/go: test with -overlay failed with a go-vet error

[hajimehoshi]

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

$ go version
go version go1.17.4 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/hajimehoshi/Library/Caches/go-build"
GOENV="/Users/hajimehoshi/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/hajimehoshi/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/hajimehoshi/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.4"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/hajimehoshi/test/overlay/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/60/khbk2xqn1c5bml1byjn89dwc0000gn/T/go-build626086560=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Prepare these files:

go.mod

module foo

foo.go

package foo

var bar = 42

foo_test.go

package foo_test

import (
        "testing"

        "foo"
)

func TestBar(t *testing.T) {
        if foo.Bar != 42 {
                t.Error("ng")
        }
}

export_test.go

package foo

var Bar = bar

replace.json

{
    "Replace": {
        "foo.go": "overlay/foo.go",
        "foo_test.go": "overlay/foo_test.go",
        "export_test.go": "overlay/export_test.go"
    }
}

overlay/foo.go

package foo

// Do nothing

overlay/foo_test.go

package foo_test

import (
        "testing"
)

func TestBar(t *testing.T) {
        // Do nothing                                                                                                                                                                                                                                                                 
}

overlay/export_test.go

package foo

// Do nothing 

And run:

go test -overlay=replace.json

What did you expect to see?

The compile and test succeed.

What did you see instead?

go-vet failed with an odd reason

$ go test -overlay=replace.json .
# foo_test
vet: ./foo_test.go:6:2: could not import foo (can't resolve import "")
FAIL    foo [build failed]
FAIL

[hajimehoshi]

Maybe duplicated with #44957?

[seankhliao]

Duplicate of #44957