Add the exception message to the log output if present

Signed-off-by: Ole Petter <ole.orhagen@northern.tech>

Author: oleorhagen

libraries/python/cfengine.py

@@ -384,6 +384,9 @@ def _handle_evaluate(self, promiser, attributes, request):
         except Exception as e:
             self.log_critical(
                 "{error_type}: {error}".format(error_type=type(e).__name__, error=e)
+                + e.message
+                if hasattr(e, "message")
+                else ""
             )
             self._add_traceback_to_response()
             self._result = Result.ERROR