https://codesandbox.io/s/elastic-mayer-rzz4h2?file=/package.json

This is supposed to `console.error` but it doesn't.

17 warns: https://codesandbox.io/s/admiring-minsky-sze07m?file=/src/App.js
setCurrentUpdatePriority(previousPriority);
    ReactCurrentBatchConfig.transition = prevTransition;
    if (executionContext === NoContext) {
      resetRenderTimer();
    }
  }
}
 Overload the definition to the two valid signatures.
 Warning, this opts-out of checking the function body.
declare function flushSync<R>(fn: () => R): R;
 eslint-disable-next-line no-redeclare
declare function flushSync(): void;
 eslint-disable-next-line no-redeclare
export function flushSync(fn) {
   
   
  if (
    rootWithPendingPassiveEffects !== null &&
    rootWithPendingPassiveEffects.tag === LegacyRoot &&
    (executionContext & (RenderContext | CommitContext)) === NoContext
  ) {
    flushPassiveEffects();
  }
  const prevExecutionContext = executionContext;
  executionContext |= BatchedContext;
  const prevTransition = ReactCurrentBatchConfig.transition;
  const previousPriority = getCurrentUpdatePriority();
  try {
    ReactCurrentBatchConfig.transition = null;
    setCurrentUpdatePriority(DiscreteEventPriority);