As a followup from How does it work? · Issue #152 · elixir-cldr/cldr · GitHub

The repo has files like de_DE, de_IT, de_AT. Why these are not valid during configuration? If the goal of all that sub packages is, to save space, then it should also be possible to just download e.g. de_AT.

defmodule WidgetWeb.Cldr do
  use Cldr,
      default_locale: "en-GB",
      locales: ["en-GB", "de-DE", "th"],
      add_fallback_locales: false,
      otp_app: :widget_web,
      providers: [Cldr.Number, Cldr.Message],
      precompile_number_formats: ["¤¤#,##0.##"],
      precompile_transliterations: [{:latn, :arab}, {:thai, :latn}],
      generate_docs: true,
      force_locale_download: false
end

== Compilation error in file lib/widget_web/services/cldr.ex ==
** (Cldr.UnknownLocaleError) Failed to install the locale named "de_DE". The locale name is not known.
    (ex_cldr 2.23.0) lib/cldr/install.ex:84: Cldr.Install.do_install_locale_name/3
    (elixir 1.12.2) lib/enum.ex:930: Enum."-each/2-lists^foreach/1-0-"/2
    (ex_cldr 2.23.0) lib/cldr/install.ex:28: Cldr.Install.install_known_locale_names/1
    (ex_cldr 2.23.0) lib/cldr.ex:81: Cldr.install_locales/1
    (ex_cldr 2.23.0) expanding macro: Cldr.Backend.Compiler.__before_compile__/1
    lib/widget_web/services/cldr.ex:1: WidgetWeb.Cldr (module)
    (elixir 1.12.2) lib/kernel/parallel_compiler.ex:319: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/7