prefersPencilOnlyDrawing is not marked as unavailale on iOS 13, but will crash app

Number:rdar://FB8614687 Date Originated:09/03/2020
Status:Open Resolved:No
Product:iOS Product Version:14
Classification: Reproducible:Yes
If you try and access UIPencilInteraction.prefersPencilOnlyDrawing on a device running iOS 13.0, it will crash the application. The behaviour is expected as UIPencilInteraction.prefersPencilOnlyDrawing is a iOS 14 property, but it is not marked as unavailable and as such compiles file for iOS 13, without throwing up a warning as other APIs would.


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