Everything was working perfectly fine in your application for multiple years. Then one day a simple configuration change of a flag resulted in over 20,000 warnings for you to handle. Welcome to Swift 6, where your working code yesterday is a compiler error today.
Source: [Dev.to](https://dev.to/adioof/swift-6-turned-working-code-into-a-compile-error-and-ios-devs-are-furious-39o9)