Do not access another task directly, use Mix.Rebar module instead

Author: José Valim

lib/mix/lib/mix/rebar.ex

@@ -1,12 +1,19 @@
 defmodule Mix.Rebar do
   @moduledoc false
+  @local_rebar_name "rebar"
 
+  # Make Mix.Rebar work like a project so we can push it into the stack.
   @doc false
   def project, do: []
 
   @doc """
-  Loads the rebar.config and evaluates rebar.config.script if it exists in the
-  given directory.
+  Return the path to the local copy of rebar. Used when building deps.
+  """
+  def local_rebar_path, do: Path.join(Mix.Utils.mix_home, @local_rebar_name)
+
+  @doc """
+  Loads the rebar.config and evaluates rebar.config.script if it
+  exists in the given directory.
   """
   def load_config(dir) do
     config_path = Path.join(dir, "rebar.config")

lib/mix/lib/mix/tasks/deps.compile.ex

@@ -137,8 +137,8 @@ defmodule Mix.Tasks.Deps.Compile do
       File.regular?("./rebar") ->
         Path.join(File.cwd!, "rebar")
 
-      File.regular?(Mix.Tasks.Local.Rebar.local_rebar_path) ->
-        Mix.Tasks.Local.Rebar.local_rebar_path
+      File.regular?(Mix.Rebar.local_rebar_path) ->
+        Mix.Rebar.local_rebar_path
 
       System.find_executable("rebar") ->
         "rebar"
@@ -152,7 +152,7 @@ defmodule Mix.Tasks.Deps.Compile do
             "dependency #{app}, please ensure rebar is available"
         end
         Mix.Task.run "local.rebar", []
-        Mix.Tasks.Local.Rebar.local_rebar_path
+        Mix.Tasks.local_rebar_path
     end
   end
 

lib/mix/lib/mix/tasks/local.rebar.ex

@@ -3,10 +3,8 @@ defmodule Mix.Tasks.Local.Rebar do
 
   import Mix.Generator, only: [create_file: 2]
 
-  @rebar_url        "https://github.com/downloads/basho/rebar/rebar"
-  @local_rebar_name "rebar"
-
-  @shortdoc "Install rebar locally"
+  @rebar_url "https://github.com/downloads/basho/rebar/rebar"
+  @shortdoc  "Install rebar locally"
 
   @moduledoc """
   Fetch a copy of rebar from the given path or url, defaulting to
@@ -16,12 +14,6 @@ defmodule Mix.Tasks.Local.Rebar do
   This version of rebar will be used as required by mix deps.compile
   """
 
-  @doc """
-  Return the path to the local copy of rebar. Used when building deps
-  """
-  def local_rebar_path, do: Path.join(local_rebar_dir, @local_rebar_name)
-  defp local_rebar_dir, do: Mix.Utils.mix_home
-
   def run(argv) do
     { _, argv } = OptionParser.parse(argv)
     do_install(case argv do
@@ -32,7 +24,8 @@ defmodule Mix.Tasks.Local.Rebar do
 
   defp do_install(path) do
     rebar = Mix.Utils.read_path(path)
-    File.mkdir_p! local_rebar_dir
+    local_rebar_path = Mix.Rebar.local_rebar_path
+    File.mkdir_p! Path.dirname(local_rebar_path)
     create_file local_rebar_path, rebar
     :file.change_mode local_rebar_path, 0755
   end