Interesting one. Fails only if Master gets chance to become active – which doesn't happen when all is easy-going. If struggling under load, it can become active and then test asserting NO ChunkCreator instance in Master fails because we want ChunkCreator now since ProcedureRegionStore was added: i.e. " // always initialize the MemStoreLAB as we use a region to store procedure now."
Here is error I've seen