format string for no primary mapper defined error, [ticket:1774]

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 7a423009964f7062ac4283f4bfad5e64bdcfbe66..ccbb273d56213203ff4cb246eee6f26c83868fa7 100644 (file)
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -337,7 +337,7 @@ class Mapper(object):
                 raise sa_exc.InvalidRequestError(
                     "Class %s has no primary mapper configured.  Configure "
                     "a primary mapper first before setting up a non primary "
-                    "Mapper.")
+                    "Mapper." % self.class_)
             self.class_manager = manager
             _mapper_registry[self] = True
             return