From the iOS 15 beta 8 notes, this may help: Using dispatch semaphores in an iOS app running in a device simulator on a Mac with Apple silicon running macOS 11 will cause the app to crash. (81783378) Workaround: In Xcode, select Product > Scheme > Edit Scheme, then deselect Run > Options > Queue Debugging > "Enable backtrace recording."

Seems to be fixed now

Same here, beta 5 seems to have corrected the issue.

I started seeing this issue in Xcode 13 beta 1 on the sim, however it did not occur when running on an actual device with iOS 15 beta, so I had assumed it was a beta sim problem. As of beta 4 it has now started happening on the device as well. Worth adding that the app breaks even though it’s a TF and built with Xcode beta 3, which ran fine (on device, as mentioned) before updating to beta 4, so I think it’s safe to assume this is an OS issue and not a toolchain issue.

@Goff.Marocchi Your link helped a lot, thanks! If I go into the SPM cache, unlock the files, and add @available(iOSApplicationExtension, unavailable) to all the classes of the cached Swift Package that's failing, then the error goes away. So at least this is a workaround. Obviously if I was using the package in an extension I'd need to annotate specific methods and so on with the same code, but in my case the class-level hack did the trick, as I only used the package in the main app target. I'll do the same as you and raise an issue for Swift Packages in my project that needed this hack in the hope we can spare others this headache.

Also experiencing this. Earlier today I also filed a radar ID FB9334019 with a sample project (nothing complex, all that’s needed is to make a new project in Xcode and add a Swift Package dependency that references UIApplication.shared). Would love to know if there’s a workaround (aside from using Cocoapods I guess :))