Xcode 16: why debug app for simulator contains additional App.dylib executable?

In Xcode 16, the presence of an additional App.dylib executable when debugging an app for the simulator is related to improvements in the build and debugging process. Xcode 16 introduces explicit modules, which enhance parallelism, diagnostics, and debugging speed. These modules allow the debugger to reuse build outputs, leading to faster debugging sessions. The App.dylib might be part of these improvements, as it could be used to facilitate the debugging process by providing necessary symbols and modules in a more efficient manner.

For more details on these improvements, you can refer to the session What’s new in Xcode 16 (08:35) where the build process and debugging enhancements are discussed.