--- a/src/HOL/Mirabelle/lib/Tools/mirabelle Sat Apr 14 23:52:17 2012 +0100
+++ b/src/HOL/Mirabelle/lib/Tools/mirabelle Sat Apr 14 23:52:17 2012 +0100
@@ -67,6 +67,8 @@
# options
+[ $# -eq 0 ] && usage
+
while getopts "L:T:O:t:q?" OPT
do
case "$OPT" in