Consistent, structured returned error value about gopher-lua HOT 3 CLOSED

package main

import (
    "github.com/yuin/gopher-lua"
    "github.com/yuin/gopher-lua/parse"
)

func myDoString(L *lua.LState, source string) error {
    fn, err := L.LoadString(source)
    if err != nil {
        if lerr := err.(*lua.ApiError); lerr != nil {
            switch cause := lerr.Cause.(type) {
            case *parse.Error:
                println("Syntax error:", cause.Error())
                println("Line: ", cause.Pos.Line)
                println("Column: ", cause.Pos.Column)
            case *lua.CompileError:
                println("Compile error:", cause.Error())
                println("Line: ", cause.Line)
            default:
                println(lerr.Error())
            }
        }
        return err
    }

    L.Push(fn)
    return L.PCall(0, lua.MultRet, L.NewFunction(func(L *lua.LState) int {
        obj := L.Get(1)
        dbg, _ := L.GetStack(1)
        L.GetInfo("Slunf", dbg, lua.LNil)
        println("Runtime error:", obj.String())
        println("Line:", dbg.CurrentLine)
        return 1 // retuens the original object
    }))
}

func main() {
    L := lua.NewState()
    myDoString(L, `
      print(1)
      print(2)
      pint(3)
      print(4)
      print(5)
    `)
}