MIX Release fails with ejabberd

Hi Forum,

I’m using the Embedded Ejabberd in an Elixir application. everything works perfectly on dev.

When I try to MIX_ENV=prod mix release I get this error:

** (Mix) :p1_utils is listed both as a regular application and as an included application.

This is the content of my Mix file:

defmodule Mantu.MixProject do
  use Mix.Project

  def project do
      app: :mantu,
      version: "0.1.0",
      elixir: "~> 1.10",
      elixirc_paths: ["lib"],
      start_permanent: Mix.env() == :prod,
      deps: deps()

  # Run "mix help compile.app" to learn about applications.
  def application do
      extra_applications: [:logger]

  # Run "mix help deps" to learn about dependencies.
  defp deps do
      {:ejabberd, "~> 20.7"}

Would appreciate some help,
Best regards,

I have some error

Erlang/OTP 22 [erts-10.6] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]

Interactive Elixir (1.11.2) - press Ctrl+C to exit (type h() ENTER for help)