do not update sandbox state if ShuttingDown is raised

docker/controller.py

@@ -317,6 +317,7 @@ class Manager:
         """
         self._shutdown = asyncio.Future()
         self._shutdown.set_exception(ShuttingDown())
+        self._shutdown.exception()  # to avoid asyncio warnings
         # cancel all 'next' tasks
         for hnd in self._handles.values():
             if hnd.nxt is not None:
@@ -724,6 +725,10 @@ EOF
                 phase = "commit"
                 yield from self._manage_commit(webapp, commit_versions)
 
+        except ShuttingDown:
+            next_state = None
+            log.info("sandbox %r %s aborted (controller shutdown)", webapp.docker_name, phase)
+
         except BaseException as e:
             next_state = fail_state