x-code:jsonデータを使ってドル円計算する

まず、foundatationをimportします。

import UIKit
import Foundation

続いて、jsonを用意します。

let jsonString:String = "{\"dollaryen\":109, \"euroen\":110}"
    var code:Int = 0

prepareでjsonを取得して計算します。

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        guard let identifier = segue.identifier else {
            return
        }
        let personalData: Data = self.jsonString.data(using: String.Encoding.utf8)!
        do {
            let items = try JSONSerialization.jsonObject(with: personalData) as! Dictionary<String,Any>
            self.code = items["dollaryen"] as! Int
        } catch {
            self.code = 1
        }
        
        
        if identifier == "showResult" {
            let CalcVC = segue.destination as! CalcViewController
            CalcVC.mySales = Int(Double(self.sales.text!)! / Double(self.code))
            CalcVC.myProfit = Int(Double(self.profit.text!)! / Double(self.code))
            CalcVC.myPrice = Int(self.price.text!)!
            CalcVC.myEPS = Double(self.eps.text!)!
        }
    }

あれ、エラーが出まくってる。。。
2018-06-03 18:42:56.527314+0900 account[17768:334563] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /Users/mac/Library/Developer/CoreSimulator/Devices/EA305F63-7A92-4933-9E03-89D80DFE7553/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2018-06-03 18:42:56.539423+0900 account[17768:334563] [MC] Reading from private effective user settings.
2018-06-03 18:42:58.597654+0900 account[17768:334563] [Common] _BSMachError: port 8c03; (os/kern) invalid capability (0x14) “Unable to insert COPY_SEND”
2018-06-03 18:43:12.349999+0900 account[17768:338350] XPC connection interrupted

buildはsucceedするが、うまくいかないです。