garble -debugdir ./test1 build
exists 'test1/test/imported/z0.go' 'test1/main/z0.go'
! grep ImportedFunc $WORK/test1/test/imported/z0.go
! grep ImportedFunc $WORK/test1/main/z0.go 


-- go.mod --
module test
-- main.go --
package main

import "test/imported"

func main() {
	imported.ImportedFunc()
}

-- imported/imported.go --
package imported

func ImportedFunc() {}