Assertion failed: About to add the priority listener twice and only one should exist on the Utterance. The listener should have been removed by removeOthersAndUpdateUtteranceWrapper.

[zepumph]

I found a bug based on recent work going on in UtteranceQueue around phetsims/joist#752.

@jessegreenberg, I think what is happening, is that when you use a single Utterance to spam a bunch of alerts through the queue for voicing, the Priority listener is still attached to that Utterance while it is speaking. Thus, if you try to add that same utterance to the queue again, it will error out because the listener is still in the map. Perhaps we need to be less strict? I'm not really sure. Over to you, let me know if you want to discuss this further.

[zepumph]

I think just testing in ratio and proportion by dragging the hands with the mouse through at least one voicing sentence.

I was also able to reproduce this in GFLB.

[jessegreenberg]

Very sorry, I am working on this now in phetsims/utterance-queue#46. You are exactly right about the breaking case.

[zepumph]

Excellent! Feel free to close this issue, and please note #1338 to help catch these in the future.

[jessegreenberg]

OK, sounds good.