2种解决办法.
Tip one: 下载Xcode 8.1 http://adcdownload.apple.com/Developer_Tools/Xcode_8.1/Xcode_8.1.xip
Tip two: 下载 10.1的镜像 https://github.com/zzBelieve/DeveloperDiskImage-Newest-10.1.git
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport 放置此文件夹后, 完全关闭Xcode重启就OK了.