diff -r 38ce8b8a980f -r 059914a691a9 entity.py
--- a/entity.py	Fri Oct 14 16:42:10 2011 +0200
+++ b/entity.py	Mon Oct 17 15:08:25 2011 +0200
@@ -333,8 +333,8 @@
                             var, order = orderterm.split()
                         except ValueError:
                             if '(' in orderterm:
-                                self.error('ignore %s until %s is upgraded',
-                                           orderterm, cmeth)
+                                cls.error('ignore %s until %s is upgraded',
+                                          orderterm, cmeth)
                                 orderterm = None
                             elif not ' ' in orderterm.strip():
                                 var = orderterm