No longer generate config for mix new

lib/mix/lib/mix/tasks/new.ex

@@ -106,9 +106,6 @@ defmodule Mix.Tasks.New do
       create_file("mix.exs", mix_exs_template(assigns))
     end
 
-    create_directory("config")
-    create_file("config/config.exs", config_template(assigns))
-
     create_directory("lib")
     create_file("lib/#{mod_filename}.ex", lib_template(assigns))
 
@@ -388,60 +385,25 @@ defmodule Mix.Tasks.New do
   end
   """)
 
-  embed_template(:config, ~S"""
-  # This file is responsible for configuring your application
-  # and its dependencies with the aid of the Mix.Config module.
-  use Mix.Config
-
-  # This configuration is loaded before any dependency and is restricted
-  # to this project. If another project depends on this project, this
-  # file won't be loaded nor affect the parent project. For this reason,
-  # if you want to provide default values for your application for
-  # third-party users, it should be done in your "mix.exs" file.
-
-  # You can configure your application as:
-  #
-  #     config :<%= @app %>, key: :value
-  #
-  # and access this configuration in your application as:
-  #
-  #     Application.get_env(:<%= @app %>, :key)
-  #
-  # You can also configure a third-party app:
-  #
-  #     config :logger, level: :info
-  #
-
-  # It is also possible to import configuration files, relative to this
-  # directory. For example, you can emulate configuration per environment
-  # by uncommenting the line below and defining dev.exs, test.exs and such.
-  # Configuration from the imported file will override the ones defined
-  # here (which is why it is important to import them last).
-  #
-  #     import_config "#{Mix.env()}.exs"
-  """)
-
   embed_template(:config_umbrella, ~S"""
-  # This file is responsible for configuring your application
-  # and its dependencies with the aid of the Mix.Config module.
+  # This file is responsible for configuring your umbrella
+  # and **all applications** and their dependencies with the
+  # help of Mix.Config.
+  #
+  # Note that all applications in your umbrella share the
+  # same configuration and dependencies, which is why they
+  # all use the same configuration file. If you want different
+  # configurations or dependencies per app, it is best to
+  # move said applications out of the umbrella.
   use Mix.Config
 
-  # By default, the umbrella project as well as each child
-  # application will require this configuration file, as
-  # configuration and dependencies are shared in an umbrella
-  # project. While one could configure all applications here,
-  # we prefer to keep the configuration of each individual
-  # child application in their own app, but all other
-  # dependencies, regardless if they belong to one or multiple
-  # apps, should be configured in the umbrella to avoid confusion.
-  import_config "../apps/*/config/config.exs"
-
-  # Sample configuration (overrides the imported configuration above):
+  # Sample configuration:
   #
   #     config :logger, :console,
   #       level: :info,
   #       format: "$date $time [$level] $metadata$message\n",
   #       metadata: [:user_id]
+  #
   """)
 
   embed_template(:lib, """

lib/mix/lib/mix/tasks/profile.cprof.ex

@@ -29,7 +29,6 @@ defmodule Mix.Tasks.Profile.Cprof do
     * `--matching` - only profile calls matching the given `Module.function/arity` pattern
     * `--limit` - filters out any results with a call count less than the limit
     * `--module` - filters out any results not pertaining to the given module
-    * `--config`, `-c` - loads the given configuration file
     * `--eval`, `-e` - evaluate the given code
     * `--require`, `-r` - requires pattern before running the command
     * `--parallel`, `-p` - makes all requires parallel

lib/mix/lib/mix/tasks/profile.eprof.ex

@@ -30,7 +30,6 @@ defmodule Mix.Tasks.Profile.Eprof do
     * `--calls` - filters out any results with a call count lower than this
     * `--time` - filters out any results that took lower than specified (in µs)
     * `--sort` - sorts the results by `time` or `calls` (default: `time`)
-    * `--config`, `-c` - loads the given configuration file
     * `--eval`, `-e` - evaluates the given code
     * `--require`, `-r` - requires pattern before running the command
     * `--parallel`, `-p` - makes all requires parallel

lib/mix/lib/mix/tasks/profile.fprof.ex

@@ -27,7 +27,6 @@ defmodule Mix.Tasks.Profile.Fprof do
     * `--callers` - prints detailed information about immediate callers and called functions
     * `--details` - includes profile data for each profiled process
     * `--sort key` - sorts the output by given key: `acc` (default) or `own`
-    * `--config`, `-c`  - loads the given configuration file
     * `--eval`, `-e` - evaluates the given code
     * `--require`, `-r` - requires pattern before running the command
     * `--parallel`, `-p` - makes all requires parallel

lib/mix/lib/mix/tasks/run.ex

@@ -45,7 +45,6 @@ defmodule Mix.Tasks.Run do
 
   ## Command-line options
 
-    * `--config`, `-c`  - loads the given configuration file
     * `--eval`, `-e` - evaluates the given code
     * `--require`, `-r` - executes the given pattern/file
     * `--parallel`, `-p` - makes all requires parallel
@@ -155,6 +154,12 @@ defmodule Mix.Tasks.Run do
   defp process_config(opts) do
     Enum.each(opts, fn
       {:config, value} ->
+        # TODO: Remove on v2.0.
+        IO.warn(
+          "the --config flag is deprecated. If you need to handle multiple configurations, " <>
+            "it is preferrable to dynamically import them in your config files"
+        )
+
         Mix.Task.run("loadconfig", [value])
 
       _ ->

lib/mix/test/mix/tasks/run_test.exs

@@ -15,8 +15,14 @@ defmodule Mix.Tasks.RunTest do
     in_tmp(context.test, fn ->
       config = fixture_path("configs/good_config.exs")
       expr = "IO.puts Application.get_env(:my_app, :key)"
-      output = capture_io(fn -> Mix.Task.run("run", ["--config", config, "--eval", expr]) end)
-      assert output == "value\n"
+
+      output =
+        capture_io(:stderr, fn ->
+          assert capture_io(fn -> Mix.Task.run("run", ["--config", config, "--eval", expr]) end) ==
+                   "value\n"
+        end)
+
+      assert output =~ "deprecated"
     end)
   after
     Application.delete_env(:my_app, :key)