android r6b version cannot compel success

the latest nkd version is r6b, in the file cocos2dx/Android.mk that only has r4 and r5 version, the diffidence between them is the driver problem. look the android-ndk changes documents, not find the changes about the driver,that means i can continue use the r5 version. but i cannot compel success. the error is “cannot find -lpng”.anyone who meet this problem, please tell me how to solve it, thanks very much.

What’s your version of cocos2d-x?
I have tested with ndk-r6, it works ok.

0.9.1.

the error picture is the cyg ouput log.