How to pretty print variables

If your goal is to avoid importing a third-party package, your other option is to use json.MarshalIndent:

x := map[string]interface{}{"a": 1, "b": 2}
b, err := json.MarshalIndent(x, "", "  ")
if err != nil {
    fmt.Println("error:", err)
}
fmt.Print(string(b))

Output:

{
    "a": 1,
    "b": 2
}

Working sample: http://play.golang.org/p/SNdn7DsBjy