diff -up chromium-67.0.3396.62/tools/gn/bootstrap/bootstrap.py.oldexec chromium-67.0.3396.62/tools/gn/bootstrap/bootstrap.py
--- chromium-67.0.3396.62/tools/gn/bootstrap/bootstrap.py.oldexec	2018-06-06 10:13:40.862084284 -0400
+++ chromium-67.0.3396.62/tools/gn/bootstrap/bootstrap.py	2018-06-06 10:14:08.809490819 -0400
@@ -112,7 +112,7 @@ def windows_prepare_toolchain(tempdir):
 
     _globals = {"__builtins__":None}
     _locals = {}
-    exec(response, _globals, _locals)
+    exec response in _globals, _locals
 
     return _locals