Use the ability to chain exceptions correctly

In the zookeeper jobboard (and persistence backends) we
are associating the cause of a new exception when raising a
exception. Using the new exception helper we can make this
work better on py2.x and py3.x so that the py3.x version
has the chain setup correctly (while the py2.x version just
uses the class 'cause' attribute instead).

Change-Id: Ieeac2f70e1834d4612556565762ffd3be3e5b5a1

1 files changed, 4 insertions, 3 deletions

diff --git a/taskflow/persistence/backends/impl_memory.py b/taskflow/persistence/backends/impl_memory.py
index 7efe6ec..0157fcf 100644
--- a/taskflow/persistence/backends/impl_memory.py
+++ b/taskflow/persistence/backends/impl_memory.py
@@ -209,10 +209,11 @@ class Connection(path_based.PathBasedConnection):
         with lock():
             try:
                 yield
-            except exc.TaskFlowException as e:
+            except exc.TaskFlowException:
                 raise
-            except Exception as e:
-                raise exc.StorageFailure("Storage backend internal error", e)
+            except Exception:
+                exc.raise_with_cause(exc.StorageFailure,
+                                     "Storage backend internal error")
 
     def _join_path(self, *parts):
         return pp.join(*parts)