Update detail.py

bakery/views/detail.py

@@ -34,7 +34,7 @@ def get_url(self, obj):
         """
         The URL at which the detail page should appear.
         """
-        if not obj.get_absolute_url():
+        if not hasattr(obj, 'get_absolute_url') or not obj.get_absolute_url():
             raise ImproperlyConfigured("No URL configured. You must either \
 set a ``get_absolute_url`` method on the %s model or override the %s view's \
 ``get_url`` method" % (obj.__class__.__name__, self.__class__.__name__))