Dialyzer returns warnings connected with dependencies

I’ve updated a version of Elixir in a project with multiple applications under umbrella project.

Elixir is updated from: 1.6.4 to 1.7.3
Erlang is updated from: 20.2 to 21.0.8 (tried also on 21.0.2)

After running mix dialyzer, There are pretty a lot of errors, we didn’t have earlier. As an example, I get following warnings, each duplicated few times:

lib/supervisor.ex:1:callback_info_missing
Callback info about the Supervisor behaviour is not available.

lib/phoenix/endpoint.ex:1:callback_info_missing
Callback info about the Plug behaviour is not available.

lib/gen_server.ex:1:callback_info_missing
Callback info about the GenServer behaviour is not available.

Our current setup of dialyzer is following:

  dialyzer: [
    plt_add_deps: :transitive,
    plt_add_apps: [:mix],
    remove_defaults: [:unknown],
    ignore_warnings: ".dialyzer/ignore-warnings",
    excluded_paths: [
      build_path() <> "/dev/lib/project_under_umbrella_1/ebin",
      build_path() <> "/dev/lib/project_under_umbrella_2/ebin"
    ]
  ],

We have only dialyzer setup in the root of the project. Such a setup is not defined under each of umbrella projects.

• I’ve tried to change, also: plt_add_deps: true - list of warnings didn’t shorten.

Do you have any other idea, I can try to remove warnings generated by libraries, we use? I would like to prevent adding such warnings to ignore_warnings file.