While working on the DevTools profiler, I've noticed that durations are sometimes incorrect. This seems to be vaguely related to high/low priority state updates. Need to track this down more so I'm filing an issue for myself.
if (returnFiber !== null) {
        
        returnFiber.firstEffect = returnFiber.lastEffect = null;
        returnFiber.effectTag |= Incomplete;
      }
      if (__DEV__ && ReactFiberInstrumentation.debugTool) {
        ReactFiberInstrumentation.debugTool.onCompleteWork(workInProgress);
      }
      if (siblingFiber !== null) {
        
        return siblingFiber;
      } else if (returnFiber !== null) {
        
        workInProgress = returnFiber;
        continue;
      } else {
        return null;
      }
    }
  }
  
  
  
  return null;
}
function performUnitOfWork(workInProgress: Fiber): Fiber | null {