env GO111MODULE=off

go list -e -f '{{.Incomplete}}' m/runbad1.go
stdout true
! go run m/runbad1.go
stderr 'use of internal package m/x/internal not allowed'

go list -e -f '{{.Incomplete}}' m/runbad2.go
stdout true
! go run m/runbad2.go
stderr 'use of internal package m/x/internal/y not allowed'

go list -e -f '{{.Incomplete}}' m/runok.go
stdout false
go run m/runok.go

cd m
env GO111MODULE=on

go list -e -f '{{.Incomplete}}' runbad1.go
stdout true
! go run runbad1.go
stderr 'use of internal package m/x/internal not allowed'

go list -e -f '{{.Incomplete}}' runbad2.go
stdout true
! go run runbad2.go
stderr 'use of internal package m/x/internal/y not allowed'

go list -e -f '{{.Incomplete}}' runok.go
stdout false
go run runok.go


-- m/go.mod --
module m

-- m/x/internal/internal.go --
package internal

-- m/x/internal/y/y.go --
package y

-- m/internal/internal.go --
package internal

-- m/internal/z/z.go --
package z

-- m/runbad1.go --
package main
import _ "m/x/internal"
func main() {}

-- m/runbad2.go --
package main
import _ "m/x/internal/y"
func main() {}

-- m/runok.go --
package main
import _ "m/internal"
import _ "m/internal/z"
func main() {}