deps.loadpaths no longer loads the dependencies, it relies simply on builds

Author: José Valim

lib/mix/lib/mix/cli.ex

@@ -49,11 +49,7 @@ defmodule Mix.CLI do
 
   defp run_task(name, args) do
     try do
-      # We need to skip loading the paths for the project and
-      # its dependencies on deps.get and deps.update to avoid
-      # having two versions of the same dep after get or update
-      # is done.
-      if not deps_task?(name) && Mix.Project.get do
+      if Mix.Project.get do
         Mix.Task.run "loadpaths", ["--no-deps-check", "--no-elixir-version-check"]
         Mix.Task.reenable "loadpaths"
         Mix.Task.reenable "deps.loadpaths"
@@ -91,10 +87,6 @@ defmodule Mix.CLI do
     IO.puts "Elixir #{System.version}"
   end
 
-  defp deps_task?("deps.update"), do: true
-  defp deps_task?("deps.get"), do: true
-  defp deps_task?(_), do: false
-
   # Check for --help or --version in the args
   defp check_for_shortcuts([first_arg|_]) when first_arg in
       ["--help", "-h", "-help"], do: :help

lib/mix/lib/mix/deps.ex

@@ -422,12 +422,6 @@ defmodule Mix.Deps do
     Mix.Deps.Lock.write(lock)
 
     unless opts[:no_compile] do
-      # TODO: This is a temporary workaround to the fact
-      # we do not loadpaths for deps.get and deps.update tasks
-      # in the CLI.
-      Mix.Task.run("deps.loadpaths", ["--no-deps-check"])
-      Mix.Task.reenable("deps.loadpaths")
-
       if apps != [] do
         args = if opts[:quiet], do: ["--quiet"|apps], else: apps
         Mix.Task.run("deps.compile", args)

lib/mix/lib/mix/tasks/deps.loadpaths.ex

@@ -1,14 +1,13 @@
 defmodule Mix.Tasks.Deps.Loadpaths do
   use Mix.Task
 
-  import Mix.Deps, only: [loaded: 0, available?: 1, load_paths: 1]
-
   @hidden true
-  @shortdoc "Load all dependencies' paths"
+  @shortdoc "Load all dependencies build paths"
 
   @moduledoc """
-  Loads all dependencies. This is invoked directly
-  by `loadpaths` when the CLI boots.
+  Loads all dependencies for the current build.
+  This is invoked directly by `loadpaths` when
+  the CLI boots.
 
   ## Command line options
 
@@ -21,8 +20,12 @@ defmodule Mix.Tasks.Deps.Loadpaths do
       Mix.Task.run "deps.check"
     end
 
-    lc dep inlist loaded, available?(dep) do
-      Enum.each(load_paths(dep), &Code.prepend_path/1)
-    end
+    config = Mix.project
+
+    Mix.Project.build_path(config)
+    |> Path.join("lib/*/ebin")
+    |> Path.wildcard
+    |> List.delete(not Mix.Project.umbrella? && Mix.Project.compile_path(config))
+    |> Enum.each(&Code.prepend_path/1)
   end
 end