edit

core.py

@@ -308,7 +308,7 @@ class Shell(object):
 			while time.time() < deadline and proc.poll() == None:
 				time.sleep(poll_seconds)
 			if proc.poll() == None:
-				os.killpg(proc.pid, signal.SIGTERM)
+				os.kill(proc.pid, signal.SIGTERM)
 				return 'timeout'
 
 			stdout,stderr = proc.communicate()