解决步骤：1. 去 Xcode Preferences -> Location -> Derived data 关闭Xcode后，删除全部文件。
2.终端运行 sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService。
不确定第一步是否有用，但是我确实这么做后运行成功。
解决方案来自Stack Overflow。下面是两个网址：
https://stackoverflow.com/questions/57159670/broken-xib-with-xcode-10-3?r=SearchResults
https://stackoverflow.com/questions/42823160/ios-build-failed-at-compile-time-with-issue-failed-to-find-a-suitable-device-fo/57159637#57159637
