What caused this React app to crash?

What caused this React app to crash?

A small CI pipeline puzzle from a very real build-system pattern. The app moves from React 18 to React 19. The next CI build runs faster than expected. Then production crashes. The clue is in the cache setup. Watch the clip and share the most likely cause in the comments. Subscribe to Google for Developers → https://goo.gle/developers Speakers: Christine Rafla