Can't find init/1 function because controller is unavailable

I’m building my first app in Phoenix. And I keep seeing this warning all the time in my router.ex file:

warning: function DummyApiWeb.CommentController.init/1 is undefined (module DummyApiWeb.CommentController is not available)
  lib/ldummy_api_web/router.ex:2

This is my router.ex :

defmodule DummyApiWeb.Router do
  use DummyApiWeb, :router

  pipeline :api do
    plug :accepts, ["json"]
  end

  scope "/api/v1", DummyApiWeb do
    pipe_through :api
    resources "/users", UserController
    resources "/clubs", ClubController do
      resources "/items", ItemController do
        resources "/comments", CommentController, only: [:create]
      end
    end

  end

  pipeline :browser do
    plug :accepts, ["html"]
  end

  scope "/", DummyApiWeb do
    pipe_through :browser
    get "/", DefaultController, :index
  end

end

And my comment_controller.ex:

defmodule DummyApi.CommentController do
  use DummyApiWeb, :controller

  def create(conn, %{"item_id" => item_id, "user_id" => user_id, "comment" => comment_params}) do
    ...

  end

end