Unity’s Frame Debugger supports Metal and should be the first tool you use to debug graphics issues in a Unity application that uses Metal. For more in-depth, Metal-specific graphics issues, Xcode provides graphics debugging tools such as API Validation and ShaderA program that runs on the GPU. More info
See in Glossary Validation. For more information, see Diagnose Metal Programming Issues Early and Viewing Your GPU Workload with the Metal Debugger.
Note: Enabling validation increases CPU resource intensity, so only enable it for debugging purposes.