UIViewController animations stop working
ios, uiviewcontroller
Solution
The described behavior has always existed: if you do work on background threads and then call and UIKit methods then more often than not the update will be delayed in a weird way.
Because of this you should always `dispatch_async` onto the main queue to update the UI.
Those bugs are very hard to catch since they do not always occur predictably.
To catch them I built a method that swizzles some UIKit methods to check if they are called on the main thread. This allows you to stop on a symbolic breakpoint, whenever you have forgotten to dispatch back onto main queue.
https://github.com/Cocoanetics/DTFoundation/blob/develop/Core/Source/iOS/Debug/UIView%2BDTDebug.m
Problem
My app runs fine in iOS6, but in an unspecified upcoming version of iOS that I cannot name for NDA reasons, all `UIViewController` transition animations stop working. New views just pop into place instantly. I am not sure if this unspecified future version of iOS is the cause, as I've seen this happen occasionally in iOS6. Sometimes animations start working for a while and then stop shortly after, making me think it's some sort of memory warning issue, but my app is using a fairly reasonable ~125MB of RAM at most times. Can anyone offer any advice or things to investigate?