Use the new Path.expand on mix

Author: José Valim

lib/mix/lib/mix/local.ex

@@ -7,7 +7,7 @@ defmodule Mix.Local do
   The path for local tasks.
   """
   def tasks_path do
-    Path.join Mix.Utils.user_home, ".mix/tasks"
+    Path.join Mix.Utils.mix_home, "tasks"
   end
 
   @doc """

lib/mix/lib/mix/utils.ex

@@ -15,11 +15,11 @@ defmodule Mix.Utils do
   """
 
   @doc """
-  Gets the user home attempting to consider OS system diferences.
+  Gets the mix home. It defaults to `~/.mix` unless the
+  MIX_HOME environment variable is set.
   """
-  def user_home do
-    System.get_env("MIX_HOME") || System.get_env("HOME") || System.get_env("USERPROFILE") ||
-      raise Mix.Error, message: "Nor MIX_HOME, HOME or USERPROFILE env variables were set"
+  def mix_home do
+    System.get_env("MIX_HOME") || Path.expand("~/.mix")
   end
 
   @doc """
@@ -285,7 +285,7 @@ defmodule Mix.Utils do
 
   @doc """
   Takes a command and converts it to a module name format.
-  
+
   ## Examples
 
       command_to_module_name("compile.elixir")

lib/mix/test/mix/tasks/local_test.exs

@@ -5,7 +5,7 @@ defmodule Mix.Tasks.LocalTest do
 
   test "manage local tasks" do
     File.rm_rf! tmp_path("userhome")
-    System.put_env "MIX_HOME", tmp_path("userhome")
+    System.put_env "MIX_HOME", tmp_path("userhome/.mix")
 
     # Install it!
     self <- { :mix_shell_input, :yes?, true }

lib/mix/test/test_helper.exs

@@ -57,7 +57,7 @@ defmodule MixTest.Case do
         Mix.Task.clear
         Mix.Shell.Process.flush
         Mix.Deps.Converger.clear_cache
-        System.put_env("MIX_HOME", tmp_path)
+        System.put_env("MIX_HOME", tmp_path(".mix"))
         del_tmp_paths
       end