XCode转换为ARC，创建通用二进制失败，错误为“无法计算体系结构类型”

I'm attempting to convert an iOS (pure Objective-C) project to ARC. The conversion fails at the octest target CreateUniversalBinary stage with the following error. The project and target architecture build settings look correct to me so I am struggling to understand why this is failing:I'm attempting to convert an iOS (pure Objectiv