--- a/main.lua	Thu Dec 17 14:24:19 2015 +0000
+++ b/main.lua	Thu Dec 17 14:24:57 2015 +0000
@@ -35,6 +35,8 @@
 			table.insert(property_rules, { class = "client", properties = { connect_host = host } });
 		elseif opt == "--out" or opt == "-o" then
 			result_log_filename = get_value();
+		else
+			error("Unhandled command-line option: "..opt);
 		end
 	end
 	assert(#arg > 0, "No test script provided");