Only print req mismatch for dependencies on compile

Author: José Valim

lib/mix/lib/mix/dep/loader.ex

@@ -202,18 +202,12 @@ defmodule Mix.Dep.Loader do
 
   defp mix_dep(%Mix.Dep{opts: opts} = dep) do
     Mix.Dep.in_dependency(dep, fn _ ->
-      config    = Mix.Project.config
       umbrella? = Mix.Project.umbrella?
 
       if umbrella? do
         opts = Keyword.put_new(opts, :app, false)
       end
 
-      if req = old_elixir_req(config) do
-        Mix.shell.error "warning: the dependency #{dep.app} requires Elixir #{inspect req} " <>
-                        "but you are running on v#{System.version}"
-      end
-
       dep = %{dep | manager: :mix, opts: opts, extra: [umbrella: umbrella?]}
       {dep, children(env: opts[:env] || :prod)}
     end)
@@ -287,11 +281,4 @@ defmodule Mix.Dep.Loader do
       {:error, _} -> {:noappfile, app_path}
     end
   end
-
-  defp old_elixir_req(config) do
-    req = config[:elixir]
-    if req && not Version.match?(System.version, req) do
-      req
-    end
-  end
 end

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

@@ -93,6 +93,11 @@ defmodule Mix.Tasks.Deps.Compile do
 
   defp do_mix(dep) do
     Mix.Dep.in_dependency dep, fn _ ->
+      if req = old_elixir_req(Mix.Project.config) do
+        Mix.shell.error "warning: the dependency #{dep.app} requires Elixir #{inspect req} " <>
+                        "but you are running on v#{System.version}"
+      end
+
       try do
         res = Mix.Task.run("compile", ["--no-deps", "--no-elixir-version-check", "--no-readd"])
         :ok in List.wrap(res)
@@ -172,4 +177,11 @@ defmodule Mix.Tasks.Deps.Compile do
       Mix.Project.build_structure(config, symlink_ebin: true)
     end
   end
+
+  defp old_elixir_req(config) do
+    req = config[:elixir]
+    if req && not Version.match?(System.version, req) do
+      req
+    end
+  end
 end

lib/mix/test/mix/tasks/deps_test.exs

@@ -84,7 +84,7 @@ defmodule Mix.Tasks.DepsTest do
       end
       """
 
-      Mix.Tasks.Deps.run []
+      Mix.Tasks.Deps.Compile.run [:ok]
 
       msg = "warning: the dependency ok requires Elixir \"~> 0.1.0\" " <>
             "but you are running on v#{System.version}"