Build errors when trying to get Mac Dev VR branch working

When I follow the readme here and I try to build the ShaderCompileWorker I get the following errors

/libs/UnrealEngine/Engine/Source/Runtime/Core/Public/CoreSharedPCH.h:58:10: Non-portable path to file '"Containers/unrealstring.h"'; specified path differs in case from file name on disk.

I get this error about 38 times.