When a struct has a map field flatpack skips the rest of the fields

[arangamani]

In the following example

package main

import (
    "fmt"

    "github.com/xeger/flatpack"
)

type Config struct {
    Database struct {
        Host []string `flatpack:"required"`
        Port int
    }
    Awesome struct {
        NotNeeded    map[string]string
        Needed       int
        ReallyNeeded string
    }

    WidgetFactory string
}

func main() {
    var config = Config{}
    err := flatpack.Unmarshal(&config)
    if err != nil {
        fmt.Printf("Failed to load configuration: %v\n", err.Error())
    }
    fmt.Println(config)
}

Running

DATABASE_HOST=[\"foo\"] AWESOME_NEEDED=10 go run main.go

doesn't populate the Needed field. But if I remove the NotNeeded map field, it works fine.