Why the field section does not get embedded

I have the following struct

package router

import (
	"io"
	"net/http"
	"townspeech/components/i18n"
	"townspeech/components/policy"
	"townspeech/components/session"
	"townspeech/controllers/base"
	"townspeech/types"
)

type sidHandler struct {
	req     *http.Request
	res     http.ResponseWriter
	handler sidFuncHandler
	section string
	err     *types.ErrorJSON
	sess    *session.Sid
}

And I want to embed in another struct like:

package router

import (
    "net/http"
    "townspeech/types"
    "townspeech/components/session"
    "townspeech/controllers/base"
)

type authHandler struct {
    sidHandler
    handler authFuncHandler
    auth    *session.Auth
}

And the function, that use the authHandler struct:

func registerAuthHandler(handler authFuncHandler, section string) http.Handler {
    return &authHandler{handler: handler, section: section}
}

The compiler complain:

# app/router
../../../router/funcs.go:9: unknown authHandler field 'section' in struct literal
FAIL	app/test/account/validation [build failed]

As you can see, the two structs are in the same package, field section should not appear as private.
What am I doing wrong?

You can't refer to promoted fields in a struct literal. You have to create the embedded type, and refer to it by the type's name.

&authHandler{
	sidHandler: sidHandler{section: "bar"},
	handler:    "foo",
}

Embedding doesn't work with literals like that.

func registerAuthHandler(handler authFuncHandler, section string) http.Handler {
    return &authHandler{
        handler: handler,
        sidHandler: sidHandler{section: section},
    }
}