Catastrophe! Your app is leaking memory. When it runs in production it crashes and starts raising
Errno::ENOMEMexceptions. So you babysit it and restart it consistently so that your app keeps responding.
As hard as you try you don’t see any memory leaks. You use the available tools, but you can’t find the leak. Understanding your full stack, knowing your tools, and good ol’ debugging will help you find that memory leak.