# goimportsbug.txt

go mod download fruit.com@v1.0.0
go mod download
goimports -l main.go

-- go.mod --
module mod

require fruit.com v1.0.0

replace fruit.com => github.com/user/banana v1.0.0

-- main.go --
package main

import (
    "fmt"

    // missing import for core below
)

func main() {
    fmt.Println(core.Orange)
}
-- core/core.go --
package core

type T struct{}
var Orange T

# mod/fruit.com_v1.0.0.txt

-- .mod --
module fruit.com

-- .info --
{"Version":"v1.0.0","Time":"2018-10-22T18:45:39Z"}

-- go.mod --
module fruit.com

-- fruit/fruit.go --
package fruit

const Apple = "apple"
-- coretest/coretest.go --
// package coretest becomes a candidate for the missing 
// core import in main above
package coretest

const Mandarin = "mandarin"

# mod/github.com_user_banana_v1.0.0.txt

-- .mod --
module fruit.com

-- .info --
{"Version":"v1.0.0","Time":"2018-10-22T18:45:39Z"}

-- go.mod --
module fruit.com

-- fruit/fruit.go --
package fruit

const Apple = "apple"
-- coretest/coretest.go --
// package coretest becomes a candidate for the missing 
// core import in main above
package coretest

const Mandarin = "mandarin"

main.go

go [list -e -json -compiled -test=false -export=false -deps=false -find=true -- ./core ./gopath/pkg/mod/fruit.com@v1.0.0/coretest ./gopath/pkg/mod/github.com/user/banana@v1.0.0/coretest .]: exit
status 1: go: directory gopath/pkg/mod/github.com/user/banana@v1.0.0/coretest outside available modules