Unable to parse slice of nested struct from JSON

Hi,
Issue somewhat similar to #117 #120 Trying to load included JSON and got strange error 'load config: load files: no such field "Url" in struct'
package main

import (
    "errors"
    "fmt"
    "os"

    "github.com/cristalhq/aconfig"
    "github.com/davecgh/go-spew/spew"
)

// Application config
type config struct {
    APIBind   string       `json:"bind_api" required:"true"`      // address to bind HTTP API
    UDPBind   string       `json:"bind_udp" required:"true"`      // address to bind UDP event receiver
    Env       string       `json:"env" default:"prod"`            // execution environment [prod|local|dev]
    Store     string       `json:"store" default:"pg"`
    TLS       TLS          `json:"tls"`                           // mTLS config
    DB        DB           `json:"database" required:"true"`      // database component
    Validator Validator    `json:"validator" required:"true"`     // validator component
    Registrar []Registrar  `json:"registrar" required:"true"`     // registrar component(s)
    Notify    NotifyClient `json:"notify_client" required:"true"` // send notify events to
}

// DB configuration.
type DB struct {
    Host     string `json:"host" required:"true"`                 // db host
    User     string `json:"user" required:"true"`                 // db auth login
    Password string `json:"password" required:"true"`             // db auth passwd
    DB       string `json:"name" required:"true"`                 // db name
    Vtable   string `json:"validator_table" required:"true"`      // validator DB table
    Rtable   string `json:"registrar_table" default:"registrant"` // registrar DB table
    TLS      TLS    `json:"tls"`                                  // mTLS config
    Port     uint16 `json:"port" default:"5432"`                  // db port
}

type TLS struct {
    CACert string `json:"cacert"`      // CA cert
    Cert   string `json:"client_cert"` // mTLS cert
    Key    string `json:"client_key"`  // mTLS key
}

// validator registrar component configuration.
type Validator struct {
    URL         string `json:"url" required:"true"`          // management URL
    ContactHost string `json:"contact_host" required:"true"` // host in contact
}

// main registrar configuration.
type Registrar struct {
    URL string `json:"url" required:"true"` // management URL
}

type NotifyClient struct {
    URL string `json:"url" required:"true"` // URL send to
}

var ErrDoMigrate = errors.New("db migrate requested")
var CFG config

func main() {
    if err := Load(); err != nil {
        fmt.Println(err)
    }

    spew.Dump(CFG)
}

func Load() error {
    loader := aconfig.LoaderFor(&CFG, aconfig.Config{
        //      FlagPrefix: "trm",
        FileFlag: "config",
        Files:    []string{"config/trunkmanager.json"},
    })
    flags := loader.Flags() // <- IMPORTANT: use this to define your non-config flags
    migrate := flags.Bool("migrate", false, "do db migrations")
    if err := flags.Parse(os.Args[1:]); err != nil {
        return err
    }
    if err := loader.Load(); err != nil {
        return err
    }
    if *migrate {
        return ErrDoMigrate
    }
    return nil
}
trunkmanager.json
cristalhq / aconfig

Unable to parse slice of nested struct from JSON #147
