$ for f in main.go fooprinter.go foo/foo.go foo/v2/foo.go; do echo -e "\n======= $f ======="; cat $f; done

======= main.go =======
package main

import "./foo"

func main() {
	foo.Print()
	printFooV2()
}

======= fooprinter.go =======
package main

import "./foo/v2"

func printFooV2() {
	foo.Print()
}

======= foo/foo.go =======
package foo

import "fmt"

func Print() {
	fmt.Println("Foo")
}

======= foo/v2/foo.go =======
package foo

import "fmt"

func Print() {
	fmt.Println("Foo V2")
}
$ go run *.go
Foo
Foo V2