--- a/marking/mark01a	Fri Mar 10 23:01:17 2017 +0000
+++ b/marking/mark01a	Wed May 31 09:26:08 2017 +0100
@@ -1,5 +1,8 @@
 #!/bin/bash
-set -e
+
+# try this to make it fail safely
+set -eu -o pipefail -posix
+#set -e
 
 out=${1:-output}