My iOS app accesses the user's Photos with ALAssetsLibrary. When I change the privacy settings for the app (Settings → Privacy → Photos), the app gets killed by system (SIGKILL). Is this a bug?
I think it is a bug or at least poorly documented and unexpected behavior. But it does not crash it is just forced to restart. You will get a SIGKILL message but no Crash log.
If you are a registered apple developer you can check their forums for discussions about this issue. Here's one.
I don't know of any way how to prevent this behavior but feel free to file a bug report with apple. It is rumored they use bug duplicates as a way of measuring the bug severity. Maybe you can store your app state in order to restore it when it restarts.