Vulkan black screen

I finally managed to get it running through Xcode, but I don’t know what I’m doing. How do I start going about debugging Vulkan / MoltenVK issues with Xcode?

Here’s the relevant output in Defold. The only thing that really stands out is VK_EXT_metal_objects was not supported but I don’t know what that means.
mvk-output.txt (7.8 KB)

And here’s what I see in Xcode. Like I said, I don’t know where to even begin: