Podfile の記載
platform :ios, "8.0"
use_frameworks!
pod 'RealmSwift'
最初、use_frameworks!を記載していなかったら、use_frameworksを書けとのエラーが。
Analyzing dependencies
Downloading dependencies
Installing Realm (0.101.0)
Installing RealmSwift (0.101.0)
[!] 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 Pod being used is: RealmSwift