CGContextTranslateCTM: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

最近在测试的过程中, 发现了SpringBoar的一个问题：

SpringBoard[53] <Error>: CGContextTranslateCTM: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

同时也发现了应用有类型的问题：

Aug  6 13:11:50  Tour1[17353] <Error>: CGContextSaveGState: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

苹果的链接如下：

https://forums.developer.apple.com/thread/13683

应该是iOS9系统引入的bug.