error: /usr/include/objc/objc-class.h: No such file or directory

Question

I am currently using blocks in my UIButton category. However I have come across this error which I cannot solve:

error: /usr/include/objc/objc-class.h:

Answer 1

Change

#import <objc/objc-class.h>

to

#import <objc/runtime.h>

From the blog entry: error: objc/objc-class.h: No such file or directory

Answer 2

Replace current line with following line:

#import <objc/runtime.h>

Thanks.

Answer 3

After xcode 4.6 this breaks again. I just fixed this like this :

cd /usr/include/
sudo ln -s /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/usr/include/objc .

Now it works like a charm