问题
I can't run the application on the simulator in the new xCode 9 beta 3 (9M174d). Every time I see the error message: (Mach error -308 - (ipc / mig) server died)
回答1:
Had this issue after installing XCode 9 beta 4. Tried every possible suggestion. The only thing that solved this issue for me was to reinstall Xcode command line tools:
Open terminal and type the command: xcode-select --install
After installation reboot the mac.
回答2:
The problem is fixed after installing the latest Mac Os Sierra patches.
来源：https://stackoverflow.com/questions/45181293/cant-run-app-in-ios-11-0-simulator