Re: unrecognized selector retainedCGImage
On Feb 19, 2019, at 02:57 , Jonathan Taylor <jonathan.taylor@...> wrote:
I suggest that you start with most mundane possibility, that this is a zombie object.
My guess is that this is one of those crashes that can happen when breaking down a UI, such as when a window is closing. It’s easy to have a dangling reference to a weakly reference object that no longer exists.
This is based on seeing:
20 Spim GUI 0x000df4cc __36-[SpimApplication stopVideoSession:]_block_invoke + 460
in the backtrace, trickling down to a KVO observer being notified:
9 Spim GUI 0x00141977 -[GUIMovieBuilder observeValueForKeyPath:ofObject:change:context:] + 119
which then looks like it’s trying to *create* a NSImage:
8 Spim GUI 0x001416b3 -[GUIMovieBuilder updateCurrentFrameImage] + 1747
which looks like it’s trying use some current window or view context:
5 AppKit 0x903d7ed8 +[NSCGImageSnapshotRep _unlockFocusAndPerformBlockUsingCGImageAndCapturingContext:] + 129
If the window has already destroyed its view hierarchy, this might not work so well.
Unfortunately, this isn’t an easy kind of problem to debug. The answer is usually to nil some non-owning “delegate” reference somewhere, but finding where and when can be challenging.