Undefined Reference To 'cv::cascadeclassifier::detectmultiscale', But Other Lib Linked Properly

I am using NDK to perform some opencv functions to see if using c++ will speed up the processing (I used Java Wrappers in another project). All was compiling fine until I added the

Solution 1:

After long investigation and testing, I found the problem located in my Application.mk. Adding the following line fix the problem;

APP_STL:=gnustl_shared

Got the idea from this response that make me think whether I'm missing stl.