Merge pull request #1 from epcim/pr/fix/fix_raise_UndefinedVariableError

fix raise of UndefinedVariableError
diff --git a/reclass/errors.py b/reclass/errors.py
index 5ce4d73..9228985 100644
--- a/reclass/errors.py
+++ b/reclass/errors.py
@@ -23,6 +23,9 @@
     message = property(lambda self: self._get_message())
     rc = property(lambda self: self._rc)
 
+    def __str__(self):
+        return self.message + '\n' + super(ReclassException, self).__str__()
+
     def _get_message(self):
         if self._msg:
             return self._msg