无法使用绝对包路径构建golang项目

I am struggling with my travis-ci build. Here the arborescence of my project:

- github.com
  - src
    - MyLib
      - MyLibImpl.go
     - main.go

The main.go is referencing MyLib like this

package main

import "fmt"
import MyLib "github.com/hako910/GolangTest/src/MyLib"

func main() {
    fmt.Printf("%v", MyLib.HelloWorld())
}

It works great on my machine but fails in travis-ci with this message:

$ go get -t -v ./...
github.com/hako910/GolangTest (download)
package github.com/hako910/GolangTest/src/MyLib: /home/travis/gopath/src/github.com/hako910/GolangTest exists but /home/travis/gopath/src/github.com/hako910/GolangTest/.git does not - stale checkout?

The command "eval go get -t -v ./... " failed. Retrying, 2 of 3.

Here is my source code https://github.com/hako910/GolangTest and here is my travis-ci build https://travis-ci.org/hako910/GolangTest/jobs/348845103

What is wrong with my configuration?