[!] Pods written in Swift can only be integrated as frameworks; add `use_frameworks!` to your Podfile or target to opt into using it. The Swift Pods being used are: ReactiveCocoa, ReactiveSwift, and Result
在podfile 里边添加 use——frameworks 就可以了
platform :ios, '8.0' pod 'Charts', '~> 2.1.6' use_frameworks!