Explicitly set env var

Author: josevalim

lib/mix/lib/mix/tasks/deps.partition.ex

@@ -21,7 +21,8 @@ defmodule Mix.Tasks.Deps.Partition do
 
   defp server(socket, deps, count, force?) do
     elixir =
-      System.find_executable("elixir") ||
+      System.get_env("MIX_OS_DEPS_COMPILE_PARTITION_ELIXIR_EXECUTABLE") ||
+        System.find_executable("elixir") ||
         raise "cannot find elixir executable for partition compilation"
 
     {:ok, {ip, port}} = :inet.sockname(socket)

lib/mix/test/test_helper.exs

@@ -49,14 +49,6 @@ ExUnit.start(
   include: line_include
 )
 
-# Clear environment variables that may affect tests
-Enum.each(
-  ~w(http_proxy https_proxy HTTP_PROXY HTTPS_PROXY) ++
-    ~w(MIX_ENV MIX_OS_DEPS_COMPILE_PARTITION_COUNT MIX_TARGET) ++
-    ~w(XDG_DATA_HOME XDG_CONFIG_HOME),
-  &System.delete_env/1
-)
-
 defmodule MixTest.Case do
   use ExUnit.CaseTemplate
 
@@ -249,6 +241,20 @@ defmodule MixTest.Case do
   end
 end
 
+# Prepare and clear environment variables
+System.put_env(
+  "MIX_OS_DEPS_COMPILE_PARTITION_ELIXIR_EXECUTABLE",
+  MixTest.Case.elixir_executable()
+)
+
+# Clear environment variables that may affect tests
+Enum.each(
+  ~w(http_proxy https_proxy HTTP_PROXY HTTPS_PROXY) ++
+    ~w(MIX_ENV MIX_OS_DEPS_COMPILE_PARTITION_COUNT MIX_TARGET) ++
+    ~w(XDG_DATA_HOME XDG_CONFIG_HOME),
+  &System.delete_env/1
+)
+
 ## Set up Rebar fixtures
 
 rebar3_source = System.get_env("REBAR3") || Path.expand("fixtures/rebar3", __DIR__)