OpenCV linker errror

[yusufkt0]

when i run build.sh there are hundreds of errors like /usr/bin/ld: /usr/lib/libopencv_*.so.4.9.0: undefined reference to 'some opencv function'. its not about the opencv version i tried some others. also tried some pull requests and changing cmakelists.txt to add 'OpenCV_LIBRARIES' instead of 'OpenCV_LIBS'. it seem like there is a collision between '/usr/lib/libopencv*' which i installed with pacman and '/usr/local/lib/libopencv*' which i installed with git . i also tried using a clean ubuntu vm and following some tutorials but didn't help either. any help is appreciated.