Do not access compile_path for umbrellas

Author: José Valim

lib/mix/lib/mix/project.ex

@@ -232,12 +232,15 @@ defmodule Mix.Project do
 
   """
   def app_path(config // config()) do
-    config[:app_path] || if app = config[:app] do
-      Path.join([build_path(config), "lib", app])
-    else
-      raise Mix.Error, message: "Cannot access build without an application name, " <>
-        "please ensure you are in a directory with a mix.exs file and it defines " <>
-        "an :app name under the project configuration"
+    config[:app_path] || cond do
+      app = config[:app] ->
+        Path.join([build_path(config), "lib", app])
+      config[:apps_path] ->
+        raise "Trying to access app_path for an umbrella project but umbrellas have no app"
+      true ->
+        raise Mix.Error, message: "Cannot access build without an application name, " <>
+          "please ensure you are in a directory with a mix.exs file and it defines " <>
+          "an :app name under the project configuration"
     end
   end
 

lib/mix/lib/mix/tasks/deps.check.ex

@@ -43,7 +43,7 @@ defmodule Mix.Tasks.Deps.Check do
       paths = Mix.Project.build_path(config)
               |> Path.join("lib/*/ebin")
               |> Path.wildcard
-              |> List.delete(Mix.Project.compile_path(config))
+              |> List.delete(not Mix.Project.umbrella? && Mix.Project.compile_path(config))
 
       to_prune = Enum.reduce(all, paths, &(&2 -- Mix.Deps.load_paths(&1)))
 

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

@@ -72,7 +72,7 @@ defmodule Mix.Tasks.Deps.Compile do
         compiled
       end
 
-    if Enum.any?(compiled), do: Mix.Deps.Lock.touch
+    if not Mix.Project.umbrella? && Enum.any?(compiled), do: Mix.Deps.Lock.touch
   end
 
   defp check_unavailable!(app, { :unavailable, _ }) do

lib/mix/test/mix/umbrella_test.exs

@@ -3,7 +3,7 @@ Code.require_file "../test_helper.exs", __DIR__
 defmodule Mix.UmbrellaTest do
   use MixTest.Case
 
-  test "compile umbrella" do
+  test "compiles umbrella" do
     in_fixture "umbrella_dep/deps/umbrella", fn ->
       Mix.Project.in_project(:umbrella, ".", fn _ ->
         Mix.Task.run "compile"
@@ -22,12 +22,16 @@ defmodule Mix.UmbrellaTest do
     end
   end
 
-  test "dependency in umbrella" do
+  test "dependencies in umbrella" do
     in_fixture "umbrella_dep/deps/umbrella", fn ->
       Mix.Project.in_project(:umbrella, ".", fn _ ->
         Mix.Task.run "deps"
         assert_received { :mix_shell, :info, ["* bar (apps/bar)"] }
         assert_received { :mix_shell, :info, ["* foo (apps/foo)"] }
+
+        # Ensure we can't compile and run checks
+        Mix.Task.run "deps.compile"
+        Mix.Task.run "deps.check"
       end)
     end
   end