Thanks for the tips. The thing is, I've checked, double-checked, triple checked and I am not accessing anything out of bounds, which is why it has worked for years without any issue. The fact that it is taking 30 seconds to compile a shader indicates something is going on and not at even at run time - so it's not out of bounds there and obviously some issue there. What concerns me the most is that the issue is completely intermittent. For given the same source code, Xcode should always produce an identical binary, but clearly it is not.

When the issue occurs, it takes 30 seconds per shader to compile - so for my main 3 shaders, it takes 1:30+ just to compile. Is there anyway to shed light on what is going on there?

I guess I will have to use a developer support issue to get to the bottom of this. It's pretty clear to me, that taking 30 seconds to compile a shader that normally compiles in 0.001 is the root of the runtime error. The compiler is obviously very confused and apparently not creating a sane binary.

Note that I cannot release my app until there is a way for the user to copy the full res image somewhere.

Enumerated shapes allows you to specify a list of multiple input and output dimensions (eg: 64, 128, 256). Flexible shapes allows you to specify a range of shape dimensions (eg 64-256) The shape for each layer is based on the input shape. Documentation for enumerated and flexible shapes.

They are, but not all layers/operators are supported.

Is 3D (stereoscopic) supported? Are there any MapKit visionOS specific features?