Xcode 12 beta and iOS 14: Weird console logs "objc[5551]: Class ... is implemented in both"

I'm having the same logs (Using Xcode Beta 3). I think it might be something with current Xcode 12 beta version.

Edit:Those logs are not appearing anymore to me.Xcode 12.0.1 (12A7300)

In my case the issue with CoreSpeech and SpeakerRecognition duplicate symbols started appearing after I accidentally deleted the dyld simulator cache in ~/Library/Developer/CoreSimulator/Caches. The cache can be restored in the following way:

1. Locate the runtime where the issue is present using xcrun simctl list -j runtimes
2. In the json object for the runtime you will hopefully find bundlePath, runtimeRoot, identifier and buildversion
3. Lookup the build version for your MacOS using sw_vers -buildVersion
4. In the $(bundlePath)/Contents/Resources directory you will find the update_dyld_sim_shared_cache executable
5. Call the update_dyld_sim_shared_cache. Specify the -root option as the runtimeRoot from the runtime json object. Specify the -cache_dir as ~/Library/Developer/CoreSimulator/Caches/dyld/$(mac_os_build_version)/$(identifier).$(buildversion).

If you are running the command on Big Sur 11.3 Beta, Xcode 12.4 and simulator runtime 14.4, the assembled update_dyld_sim_shared_cache call will look like this:

/Applications/Xcode12.4.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/update_dyld_sim_shared_cache -root /Applications/Xcode12.4.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot -cache_dir ~/Library/Developer/CoreSimulator/Caches/dyld/20E5196f/com.apple.CoreSimulator.SimRuntime.iOS-14-4.18D46

This problem was solved for me by deleting Xcode 12.5.1 and re-installing it. I see a comment here from myjunk recommending that and yes, it work for me.

I also have the Xcode 13 beta installed on this machine alongside the release version. I built and ran the same project on the Xcode beta where the issues had been seen on Xcode 12.5.1 without problems, and then more importantly returning to Xcode 12.5.1 the problem was still solved. Reinstalling Xcode 12.5.1 did the trick, and it looks like you don't have to worry that also using the beta will necessarily cause them to return...