diff -r e150b4bcbfaa -r 28a346df670e migration.py
--- a/migration.py	Thu Aug 30 17:07:59 2012 +0200
+++ b/migration.py	Thu Aug 23 11:43:43 2012 +0200
@@ -514,7 +514,9 @@
                     elif op == None:
                         continue
                     else:
-                        print 'unable to handle this case', oper, version, op, ver
+                        print ('unable to handle %s in %s, set to `%s %s` '
+                               'but currently up to `%s %s`' %
+                               (cube, source, oper, version, op, ver))
             # "solve" constraint satisfaction problem
             if cube not in self.cubes:
                 self.errors.append( ('add', cube, version, source) )