前几天清理了Xcode里面的文件，再次运行编译成功，模拟器安装app时出现报错：
Failed to create temporary staging dir
Failed to install
尝试用另外一个模拟器，提示：
Unable to boot device because it cannot be located on disk
Use the device manager in Xcode or the simctl command line tool to either delete the device properly or erase contents and settings
清理模拟器试试：
xcrun simctl list
找到对应模拟器的Identifier
xcrun simctl erase 6EB26FB3-F34B-42F3-8A6B-C5601C02D55A
再次运行就可以了。
