--- a/runtime/spawn_subprocess.py	Fri Mar 22 11:10:37 2019 +0100
+++ b/runtime/spawn_subprocess.py	Fri Mar 22 13:26:31 2019 +0100
@@ -3,6 +3,7 @@
 
 # subset of subprocess built-in module using posix_spawn rather than fork.
 
+from __future__ import print_function
 from __future__ import absolute_import
 import os
 import signal