Allow mix/apps configuration via ~/.mix/config.exs

Author: José Valim

lib/mix/lib/mix/cli.ex

@@ -20,6 +20,7 @@ defmodule Mix.CLI do
 
   defp proceed(args) do
     Mix.Tasks.Local.Hex.maybe_update()
+    load_dot_config()
     args = load_mixfile(args)
     {task, args} = get_task(args)
     change_env(task)
@@ -98,6 +99,15 @@ defmodule Mix.CLI do
     end
   end
 
+  defp load_dot_config do
+    path = Path.expand("~/.mix/config.exs")
+    if File.regular?(path) do
+      path
+      |> Mix.Config.read()
+      |> Mix.Tasks.Loadconfig.set()
+    end
+  end
+
   defp display_version() do
     IO.puts "Elixir #{System.version}"
   end