Xcode 11.1 GM Seed的iOS Simulator无法启动iOS 13.1设备求助

Hey there, let's get to the bottom of this frustrating simulator issue so you can focus on learning Swift smoothly. Here's what's going on and how to fix it:

What's Causing the Problem? #

Your core issue is the incompatibility between MacOS Mojave 10.14.6 and the iOS 13.1 simulator included in Xcode 11.1 GM Seed. The SIGILL signal crashing SpringBoard means the simulator is trying to execute a CPU instruction that Mojave doesn't support. Those duplicate objc class warnings in your logs are just noise—they aren't the root cause of the crash.

Solutions to Try #

1. Upgrade MacOS to Catalina (10.15+) #

This is the most reliable fix. Xcode 11 and later versions of the iOS simulator are designed to work best with MacOS Catalina and newer. Mojave lacks the low-level system support needed to run the iOS 13 simulator smoothly. Upgrading will eliminate the illegal instruction error and let you use all iOS 13+ features without issues.

2. Stick with iOS 12.2 Simulator (and Adjust Your Project) #

If you can't upgrade your MacOS right now, you can keep using the iOS 12.2 simulator and tweak your project to avoid compatibility errors:

• Lower your project's deployment target:
  1. Open your project in Xcode, then select the top-level project icon in the left sidebar.
  2. Go to the Info tab, find the Deployment Target dropdown, and set it to iOS 12.2.
• Use a UIKit-based template instead of SwiftUI:
  Xcode 11 defaults to SwiftUI for new projects, which is iOS 13+. If you create a new project, choose the "Single View App" template and make sure User Interface is set to Storyboard (not SwiftUI) to get code compatible with iOS 12.
• Fix iOS 13-specific code:
  If you see errors about some View or other SwiftUI features, replace them with UIKit equivalents (like UIViewController and UIView) or use conditional compilation to only run iOS 13 code on newer systems:

  if #available(iOS 13.0, *) {
      // iOS 13+ code here
  } else {
      // iOS 12 fallback code here
  }
  

3. Clean Up and Reinstall Xcode (If Needed) #

If the above steps don't help, try a fresh install of Xcode to rule out corrupted files:

• Fully uninstall Xcode:
  1. Drag /Applications/Xcode.app to the Trash.
  2. Delete these support folders:
     • ~/Library/Developer/Xcode
     • ~/Library/Caches/com.apple.dt.Xcode
• Download the official release version of Xcode 11 (not the GM Seed) from the App Store or Apple's developer portal—GM builds sometimes have unpatched bugs fixed in the final release.
• After reinstalling, reset the simulator again with Erase All Contents and Settings, then restart your Mac before launching the simulator.

内容的提问来源于stack exchange，提问作者Tom