Got this debugging another error. Filing here for reference. Original code: https://phabricator.intern.facebook.com/P59317705
): Fiber | null {
    invariant(
      !isWorking,
      'renderRoot was called recursively. This error is likely caused ' +
        'by a bug in React. Please file an issue.',
    );
    isWorking = true;
    
    
    if (
      expirationTime !== nextRenderExpirationTime ||
      root !== nextRoot ||
      nextUnitOfWork === null
    ) {
      
      resetStack();
      nextRoot = root;
      nextRenderExpirationTime = expirationTime;
      nextUnitOfWork = createWorkInProgress(
        nextRoot.current,
        null,
        nextRenderExpirationTime,
      );
      root.pendingCommitExpirationTime = NoWork;
    }
    let didFatal = false;
    startWorkLoopTimer(nextUnitOfWork);
    do {
      try {
        workLoop(isAsync);