原因是Xcode 10中將libstdc++.6.0.9庫文件刪除，原本功能遷移至其他庫.
在終端輸入以下命令打開Xcode的lib庫目錄，放入libstdc++.6.0.9.
真機運行庫
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib
模擬器運行庫
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib