Golang import cycle not allowed

example_test.go

Source: https://github.com/go-fsnotify/fsnotify
Direct link: https://github.com/go-fsnotify/fsnotify/blob/master/example_test.go

Error:

~/gocode/src/github.com/go-fsnotify/fsnotify $ go build example_test.go
import cycle not allowed
package runtime
	imports runtime/internal/atomic
	imports runtime
	
Go repo is cloned to ~/go today 2015-12-03.

------------------

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build !plan9,!solaris

package fsnotify_test

import (
	"log"

	"github.com/go-fsnotify/fsnotify"
)

func ExampleNewWatcher() {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Fatal(err)
	}
	defer watcher.Close()

	done := make(chan bool)
	go func() {
		for {
			select {
			case event := <-watcher.Events:
				log.Println("event:", event)
				if event.Op&fsnotify.Write == fsnotify.Write {
					log.Println("modified file:", event.Name)
				}
			case err := <-watcher.Errors:
				log.Println("error:", err)
			}
		}
	}()

	err = watcher.Add("/tmp/foo")
	if err != nil {
		log.Fatal(err)
	}
	<-done
}