I would like to know whether and how people are getting the sandbox account > manage > clear purchase history feature to work. I clear purchase history (either on my device or at app store connect), and I delete my app from my device. I then run my app from Xcode on my device, and it detects at launch the existence of the purchase, and so I cannot test my purchase user interface. Does this thing actually work as advertised?

In the Xcode 13 beta, where's the Vary For Traits button?

Where is the sample code example for WWDC 2016 video 216 (on advances in UIKit view animation)? Should be called something like Photos and should have an example of an animation that can be interrupted, scrubbed, and restarted.

Why does WWDC 2015 video 510 claim that it works to put a UIImage generated by calling UIImage(CIImage:) in a UIImageView? This has _never_ worked, and it still doesn't. The code they use is like this:imageview.image = UIImage(CIImage:ciimage)That displays nothing. The only way to display a UIImage based on a CIImage is to _render_ it, _explicitly_. A UIImageView is not going to magically do this for you. For example, in my own code, where the CIImage is called `blendimage`, this works fine: UIGraphicsBeginImageContextWithOptions(myextent.size, false, 0) UIImage(CIImage: blendimage).drawInRect(myextent) let im = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() self.iv.image = imBut this does nothing: the image view is blank: self.iv.image = UIImage(CIImage: blendimage)The video surely would not be making this explicit radical claim if it isn't true. But it isn't true. So why do they make it? Is it _supposed_ to work but failing? Or have I just been missing something all these years that would make that line of code magically work?

When I use PHPickerViewController to let the user choose a photo, and I run my app in the Simulator, there is some issue with just the first photo in the library. If the user chooses that photo and we say guard let result = results.first else { return } let prov = result.itemProvider print(prov.registeredTypeIdentifiers) prov.loadObject(ofClass: UIImage.self) { (result, err) in     print(result) } we are told that the registered type identifiers are ["public.jpeg", "public.heic"], and then when we ask for UIImage we get an error: "The file ... couldn’t be opened because there is no such file." And the resulting UIImage is nil. The problem arises only for this one photo, and it is the only one with an HEIC representation. Is there some issue with photos that have an HEIC representation? How are we supposed to retrieve the image for these? (The same code works just fine on a device. The issue arises only on the Simulator. I'm using the latest Xcode 12.2 beta.)

In WWDC 2018 video 220, minute 28:00, the presenter says "we're going to be introducing a new Instrument for layout".That was back in the beginning of June. It's now the middle of August. We're on Xcode 10 beta 6. I don't see this instrument. Where is it?