Build Errors when Building Unreal + Flex in Xcode

I have been working on getting the github source for Flex integration in Unreal built on my MacBook Pro, but I have ran into build errors when I try to build UE4 with the target as MyMac in Xcode. I was able to get it working on my Windows laptop, but its integrated GPU is pretty bad.

Here is the Error: “ISO C++ forbids forward references to ‘enum’ types” in HairWorksFactory.h, HairWorksComponent.h, and HairWorksAsset.h

Has anyone ran into this issue and how can I get around these errors?
Are there specific versions of the Apple LLVM, GCC, or C++ that I should be using?

Any advice would be greatly appreciated


I’ve been having the same issue, would be ecstatic if there are any solutions.