Xcode 12.5 Debugger Slow Since macOS Big Sur 11.3 (Native Swift Project) [closed]

Question

I just updated macOS Big Sur 11.3 today. Nothing is weird until I open Xcode and run my app in simulator. The app launch is becoming veryyy slow and sometimes it crash when there is background thread like URLSession. I have xcode 12.5 before in macOS 11.2.1 and no problem with debugging dan running in simulator.

These are what I have done so far but still no luck:

• Try create new blank project, problem still exist
• Clean derived data
• Clean project
• Force quit xcode.
• Restart macbook

These are my assumtion of solution but still have no chance to do right now:

• Reinstall iOS 14 simulator/ install another simulator with different OS version (I will try this when I am in somewhere with high speed internet connection)
• Reinstall xcode (Still no high speed internet connection)
• Downgrade macOS and xcode (Still no high speed internet connection)
• Install di real device (I have no single iphone)

Have you experience this? How to solve this problem? I have not tested in real device because I don't have iOS device.

Answer 1

This is already discussed in Apple Developer Forum lately. Still not sure what’s going on here, but some people pointed out about dyld being slowed down after macOS Big Sur 11.3. So this has nothing to do with Xcode. All Xcode version in macOS 11.3 (maybe) get affected with this issue. Apple should release macOS update to resolve this issue.

In my case, this issue only appear in Simulator. It is normal in real device. My advice is try to run it in real device and wait for Apple to fix this. But if you only can run your app in Simulator, you should untick/uncheck the debug executable option in Edit Scheme -> Run

Update: The downside of uncheck the debug executable is you are no longer use debugger. So some feature like breakpoint will not work.

Update: Some people with macOS Big Sur 11.4 also reporting that this issue still exist.

Update: This bug has been fixed in macOS Monterey Beta and Xcode 13 Beta.