Pausing a plan returns an event containing an error

[joeshannon]

When pausing the run engine via blueapi (blueapi controller pause) the status message looks like this:

{
   "state":"PAUSED",
   "task_status":{
      "task_id":"977ad14b-e009-43cc-9a6a-4fd3a77c1c08",
      "task_complete":true,
      "task_failed":true
   },
   "errors":[
      "\nYour RunEngine is entering a paused state. These are your options for changing\nthe state of the RunEngine:\n\nRE.resume()    Resume the plan.\nRE.abort()     Perform cleanup, then kill plan. Mark exit_stats='aborted'.\nRE.stop()      Perform cleanup, then kill plan. Mark exit_status='success'.\nRE.halt()      Emergency Stop: Do not perform cleanup --- just stop.\n"
   ],
   "warnings":[
      
   ]
}

Since the errors list is populated, this is considered an error by clients so they might stop listening to relevant events.

Additionally the message content should not really be sent via blueapi as this is designed for using the RE in an interpreter.

[stan-dot]

potential solutions:

• move from error to warning (easy)
• do not send any message at all

[stan-dot]

details:
if new_state == WorkerState.PAUSED: handler.pause_worker(defer=state_change_request.defer)

lines 264 and 265 in blueapi/service/main.py.

Going deeper now.

[stan-dot]

reworker.py def pause(self, defer=False): LOGGER.info("Requesting to pause the worker") self._ctx.run_engine.request_pause(defer)
: 214

[stan-dot]

def request_pause(self, defer=False): """ Command the Run Engine to pause.
bluesky/run_engine : 751

[stan-dot]

also event.py:
class WorkerEvent(BlueapiBaseModel) 105

[stan-dot]

reworker.py .
: 271
def _on_state_change( self, raw_new_state: RawRunEngineState, raw_old_state: RawRunEngineState | None = None, ) -> None: new_state = WorkerState.from_bluesky_state(raw_new_state) if raw_old_state: old_state = WorkerState.from_bluesky_state(raw_old_state) else: old_state = WorkerState.UNKNOWN LOGGER.debug(f"Notifying state change {old_state} -> {new_state}") self._state = new_state self._report_status()

[stan-dot]

it's deep in the entrails of RunEngine, that assumes a pause is an error.

it's not a blueapi issue perhaps