IOS coreData 编译出错

Cannot find cdtool at '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/Xcode/Agents/cdtool': Cannot find a simulator runtime for platform <DVTPlatform:0x7fd67af0a930:'com.apple.platform.iphonesimulator':<DVTFilePath:0x7fd67af0a7c0:'/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform'>>.

以上是出现错误列子 ，找了好多原因，结果在外网找到一个解决方案： 传送门：

https://stackoverflow.com/questions/44471971/xcode-9-bug-cannot-find-cdtool

第一步是打开‘终端’ 然后打开root用户 命令：sudo -i

接下来输入：

sudo mkdir /Library/Developer/CoreSimulator/Profiles/Runtimes/Backup sudo mv /Library/Developer/CoreSimulator/Profiles/Runtimes/{,Backup/}iOS\ 10.3.simruntime sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService

之后重启Xcode 以及 模拟器

然后输入：installer -pkg /Applications/Xcode-beta.app/Contents/Resources/Packages/XcodeSystemResources.pkg -target /

我是这么操作的，然后CoreData项目可以正常运行； （记录一下，以后遇到再也不纠结了。。。）