This DEV-only field was added in 836331ba5f69f2cc53b273ec073fae116db14302 by @sebmarkbage but it's not being used anymore to my knowledge.
Component,
          nextProps,
          context,
          renderLanes,
        );
      } finally {
        reenableLogs();
      }
    }
    setIsRendering(false);
  } else {
    nextChildren = renderWithHooks(
      current,
      workInProgress,
      Component,
      nextProps,
      context,
      renderLanes,
    );
  }
  if (current !== null && !didReceiveUpdate) {
    bailoutHooks(current, workInProgress, renderLanes);
    return bailoutOnAlreadyFinishedWork(current, workInProgress, renderLanes);
  }
  
  workInProgress.flags |= PerformedWork;
  reconcileChildren(current, workInProgress, nextChildren, renderLanes);
  return workInProgress.child;
}
function updateClassComponent(