sdl2_metal: Undefined symbols for architecture arm64

Hello, I'm trying to run sdl2_metal example but I get this error, any clues?

Undefined symbols for architecture arm64:
  "___$objc_SEL$init", referenced from:
      _objc_Metal::RenderPassDescriptor_init in sdl2_metal-objc_Metal-120de1e10.o
ld: symbol(s) not found for architecture arm64