Hey!
I need some help cause I’m facing the exact same issue. I have both pre and post build scripts that copy image resources inside my app and my AUv3 app extension.
When using Xcode-9.4.1 the app archives correctly as an iOS App. When using Xcode 10.0 though, it’s been archived as a Generic XCode Archive, which as you said above cannot be submitted to the App Store Connect.
The difference between the two archives (Xcode 9.4.1 vs 10.0) is that the wrong one of Xcode 10.0 contains JUCE’s static library of my plugin’s shared code, libMyApp.a.
Any suggestions on how I can fix this with Xcode 10.0? As far as I’m concerned, I have to use Xcode 10.0 in order for my app to be able to run in iOS 12 iDevices - right?
Thanks!