Symbol not found _OBJC_IVAR_$_NSView._layer (in AppKit) only on 10.7, works fine on 10.8 and 10.9

问题

My mac cocoa app works fine on 10.8 and 10.9 except on 10.7 (fresh install) with this error at start : Symbol not found: _OBJC_IVAR_$_NSView._layer

Process:         xxx [875]
Path:            /Users/USER/Desktop/xxx.app/Contents/MacOS/xxx
Identifier:      com.xxx.xxx
Version:         1.0 (1)
Code Type:       X86-64 (Native)
Parent Process:  launchd [127]

Date/Time:       2014-02-13 17:44:24.208 +0100
OS Version:      Mac OS X 10.7.5 (11G63)
Report Version:  9

Crashed Thread:  0

Exception Type:  EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000

Application Specific Information:
dyld: launch, loading dependent libraries

Dyld Error Message:
  Symbol not found: _OBJC_IVAR_$_NSView._layer
  Referenced from: /Users/USER/Desktop/xxx.app/Contents/MacOS/xxx
  Expected in: /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
 in /Users/USER/Desktop/xxx.app/Contents/MacOS/xxx

(xxx = appname)

I checked on system disk, AppKit framework is fine in the forlder /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit

Weird, isn't it ? Thank you for any help ...

回答1:

I fixed the issue by remove this lines in all of my code :

//self.layer = _layer; //Not necessary at all
self.wantsLayer = YES; //Necessary since 10.8

Thank you so much for help!

来源：https://stackoverflow.com/questions/21760465/symbol-not-found-objc-ivar-nsview-layer-in-appkit-only-on-10-7-works-fine