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
while (current !== null) {
      const primarySubtreeFlag = current.subtreeFlags & fiberFlags;
      if (
        current !== subtreeRoot &&
        current.child !== null &&
        primarySubtreeFlag !== NoFlags
      ) {
        current = current.child;
      } else {
        if ((current.flags & fiberFlags) !== NoFlags) {
          invokeEffectFn(current);
        }
        if (current.sibling !== null) {
          current = current.sibling;
        } else {
          current = subtreeRoot = current.return;
        }
      }
    }
  }
}
let didWarnStateUpdateForNotYetMountedComponent: Set<string> | null = null;
function warnAboutUpdateOnNotYetMountedFiberInDEV(fiber) {
  if (__DEV__) {
    if ((executionContext & RenderContext) !== NoContext) {
       W
      return;
    }
    if (!(fiber.mode & ConcurrentMode)) {
      return;