iOS上的SceneKit：使用Swift编写的计时功能崩溃

Question

I'm trying to write a custom timingFunction for a SCNAction in a Swift project. It is supposed to have the signature (Float) -> Float and return a value between 0.0 and 1.0. But whatever value I return, the app will always crash with a EXC_BAD_ACCESS saying "error: memory read failed for 0xd0000000" when the action is run.

This is the most basic function I could come up with to demonstrate the problem:

var action = SCNAction.moveByX(0, y: 100, z: 0, duration: 1)
action.timingFunction = { time in
    return time
}
someSCNNode.runAction(action)

The same code in Objective-C works just fine.

I've tested this with iOS 8.0.1, 8.0.2 and 8.1b2 with several devices and simulators. Am I doing something wrong here or is this a Swift bug?

Answer 1

Looks like a bug — it works on the shipping OS X Yosemite release. File a report with Apple and they'll probably notify you when the fix makes it into iOS.