Bug #1704790: bind name "sys" locally in __del__ method so that it is
not cleared before __del__ is run.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 80a60b9..11fc439 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -628,7 +628,7 @@
         return data
 
 
-    def __del__(self):
+    def __del__(self, sys=sys):
         if not self._child_created:
             # We didn't get to successfully create a child process.
             return