iOS 8 SpriteKit 在从块/动作添加或删除孩子时崩溃

从 iOS8 开始，我的游戏突然开始崩溃.经过一番调试，我发现游戏在以下两个地方崩溃:

As of iOS8 my game started to crash all of a sudden. After a bit of debugging I have found that the game crashes in the two following places :

 [sparkNode runAction:[SKAction sequence:@[
                                           //Some actions and finally...
                                           [SKAction removeFromParent]]]]; // Crashes here (If I remove this action no crash occurs)

还有第二名:

[rankTransitionSprite runAction:[SKAction sequence:@[[SKAction scaleTo:1.5 duration:1.0],
                                                     [SKAction runBlock:^{
    CGPoint rankPosition = _rankSprite.position;
    [_rankSprite removeFromParent];
    _rankSprite = [_spritesFactory spriteFromAtlasForImageName:[NSString stringWithFormat:@"rank%d", rank]];
    [self addChild:_rankSprite]; // Crashes here
}],
                                                     [SKAction scaleTo:0.0 duration:1.0],
                                                     [SKAction removeFromParent]]]];

在 iOS 7.1 上不会发生崩溃.它只在 iOS8 上崩溃.对于第一次崩溃，我将 removeFromParent 操作替换为:

On iOS 7.1 the crash does NOT occur. It only crashes on iOS8. For the first crash I replaced the removeFromParent action with :

[SKAction runBlock:^{
                      dispatch_async(dispatch_get_main_queue(), ^{
                           [sparkNode removeFromParent]; 
                      });
}]

这似乎解决了问题.

对于第二次崩溃，我做了同样的事情(在主线程中添加精灵)并且崩溃消失了.

For the second crash I did the same thing (Adding the sprite in the main thread) and the crash was gone.

崩溃日志:

Thread 0 Crashed:: Dispatch queue: com.apple.spritekit.renderQueue
0   SpriteKit                       0x000000010abed9fe SKCRenderer::preprocessSpriteImp(std::__1::vector<SKCRenderer::SpriteRenderInfo, std::__1::allocator<SKCRenderer::SpriteRenderInfo> >&, SKRenderQuadPool&, SKCSprite const*, _GLKMatrix4 const&, float, unsigned int&, bool)   372
1   SpriteKit                       0x000000010abee82b SKCRenderer::preprocessSpriteImp(std::__1::vector<SKCRenderer::SpriteRenderInfo, std::__1::allocator<SKCRenderer::SpriteRenderInfo> >&, SKRenderQuadPool&, SKCSprite const*, _GLKMatrix4 const&, float, unsigned int&, bool)   4001
2   SpriteKit                       0x000000010abee82b SKCRenderer::preprocessSpriteImp(std::__1::vector<SKCRenderer::SpriteRenderInfo, std::__1::allocator<SKCRenderer::SpriteRenderInfo> >&, SKRenderQuadPool&, SKCSprite const*, _GLKMatrix4 const&, float, unsigned int&, bool)   4001
3   SpriteKit                       0x000000010abe7c21 SKCRenderer::preprocessAndSubmitSpriteInternal(std::__1::vector<SKCRenderer::SpriteRenderInfo const*, std::__1::allocator<SKCRenderer::SpriteRenderInfo const*> >&, std::__1::vector<SKCRenderer::SpriteRenderInfo, std::__1::allocator<SKCRenderer::SpriteRenderInfo> >&, SKRenderQuadPool&, SKCSprite const*, _GLKMatrix4 const&)   139
4   SpriteKit                       0x000000010abeb7d1 SKCRenderer::submitScene(SKScene*, bool)   393
5   SpriteKit                       0x000000010abeff16 SKCRenderer::renderScene(SKScene*, bool)   86
6   SpriteKit                       0x000000010ab87542 -[SKView _renderContent]   1027
7   libdispatch.dylib               0x000000010c974b94 _dispatch_client_callout   8
8   libdispatch.dylib               0x000000010c9611e7 _dispatch_barrier_sync_f_invoke   76
9   SpriteKit                       0x000000010ab870f3 -[SKView renderContent]   89
10  SpriteKit                       0x000000010ab8415c __29-[SKView setUpRenderCallback]_block_invoke   54
11  SpriteKit                       0x000000010abb0a54 -[SKDisplayLink _callbackForNextFrame:]   256
12  QuartzCore                      0x000000010ecf0967 CA::Display::DisplayLinkItem::dispatch()   37
13  QuartzCore                      0x000000010ecf082f CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long)   315
14  CoreFoundation                  0x000000010b39e4d4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__   20
15  CoreFoundation                  0x000000010b39e095 __CFRunLoopDoTimer   1045
16  CoreFoundation                  0x000000010b3613cd __CFRunLoopRun   1901
17  CoreFoundation                  0x000000010b3609f6 CFRunLoopRunSpecific   470
18  GraphicsServices                0x000000010d41d9f0 GSEventRunModal   161
19  UIKit                           0x00000001098cb990 UIApplicationMain   1282

我的问题是为什么它只在 iOS8 上崩溃?(在许多 iOS 7.1 测试中它从未崩溃过)

And my question is why does it crash only on iOS8? (on many iOS 7.1 tests it never crashed)