Mac OS X use /private as directory to temp file

Related with e62ddac0

railties/test/generators/plugin_test_runner_test.rb

@@ -70,7 +70,7 @@ def test_output_inline_by_default
     create_test_file 'post', pass: false
 
     output = run_test_command('test/post_test.rb')
-    assert_match %r{Running:\n\nPostTest\nF\n\nwups!\n\nbin/test #{plugin_path}/test/post_test.rb:6}, output
+    assert_match %r{Running:\n\nPostTest\nF\n\nwups!\n\nbin/test (/private)?#{plugin_path}/test/post_test.rb:6}, output
   end
 
   def test_only_inline_failure_output