[BUG] iOS Value Null When First Time Accessing BlobCache

[albilaga]

Describe the bug
I got error value is null on akavache. This is happened only when app get deployed into real device via testflight. Not happening when using debug or even release mode in real device. After rge

Steps To Reproduce

1. Add Akavache and AppCenter into iOS and Xamarin.Forms project
2. Add

Akavache.Registrations.Start("Mobile Timesheet");
BlobCache.ForcedDateTimeKind = DateTimeKind.Local;
BlobCache.EnsureInitialized();

in App.xaml.cs constructor
3. Add some service to use Akavache
4. Deploy in real device via testflight with linker behavior : Link SDK only
5. When accessing akavache it got error Value cannot be null. Parameter name: source
6. This is not happen when debug or release mode in real device without testflight

Expected behavior
The app should can access akavache even when deployed via testflight

Environment

• OS: iOS 13.6, iOS 14.0
• Version: 6.10.20

[albilaga]

Just got notified from my coworker that it is working with adding

[Preserve]
    public static class LinkerPreserve
    {
        static LinkerPreserve()
        {
            throw new Exception(typeof(SQLitePersistentBlobCache).FullName);
        }
    }


    public class PreserveAttribute : Attribute
    {
    }

which should be not needed according to docs if already have

Akavache.Registrations.Start("Mobile Timesheet");

Maybe we should update the docs?