--- a/checker.py	Thu Jun 23 14:38:55 2016 +0800
+++ b/checker.py	Thu Jun 23 14:58:09 2016 +0800
@@ -112,12 +112,20 @@
     print('# C&O job finished: {}'.format(now()))
 
 
+def bad_exit():
+    print('# C&O job failed (exception not caught)')
+    print('# C&O job finished: {}'.format(now()))
+
+
 def main():
     parser = ArgumentParser()
     parser.add_argument('config', help='configuration file (YAML)', type=FileType('r'))
     args = parser.parse_args()
     config = yaml.safe_load(args.config)
-    execute(config)
+    try:
+        execute(config)
+    except:
+        bad_exit()
 
 
 if __name__ == '__main__':