--- a/checker.py	Sun Jul 03 23:00:17 2016 +0800
+++ b/checker.py	Sun Jul 03 23:04:08 2016 +0800
@@ -102,7 +102,7 @@
         print('# C&O task: setup')
         linter_config = {}
 
-        for linter in config['linters']:
+        for linter in config.get('linters', []):
             if 'name' not in linter:
                 continue
 
@@ -127,7 +127,7 @@
 
     if ok:
         print('# C&O task: checks')
-        for linter in config['linters']:
+        for linter in config.get('linters', []):
             if 'name' not in linter or 'include' not in linter:
                 continue