Execute runtime.exs in custom mix task

[derheap]

A student of mine (jojofreddy) pointed me to this:

Config/runtime.exs not loaded on mix tasks

I was able to achieve that by running mix app.config first. mix app.config Loads and configures all registered apps. This is done by loading config/runtime.exs if one exists. So to see it works you could try running them like: mix do app.config, something And to make your task running it automatically - you could call it as a first thing to do in run/1 function def run(_args) do Mix.Task.run("app.config") IO.inspect(Application.get_env(:test, :port)) ...

This magic line

def run(args) do
    Mix.Task.run("app.config")
  # do work
end

solved the problem.