Video Codec SDK samples building error

Hello I am new to Nvidia Video Codec SDK , I downloaded Nvidia Video Codec SDK 12.0 and I am trying to build the samples I run cmake command and its ok but when I run make I get this error:

/usr/bin/ld: CMakeFiles/AppDecGL.dir/FramePresenterGLX.cpp.o: undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
/usr/bin/ld: /lib/x86_64-linux-gnu/ error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [AppDecode/AppDecGL/CMakeFiles/AppDecGL.dir/build.make:317: AppDecode/AppDecGL/AppDecGL] Error 1
make[1]: *** [CMakeFiles/Makefile2:472: AppDecode/AppDecGL/CMakeFiles/AppDecGL.dir/all] Error 2
make: *** [Makefile:130: all] Error 2

for your information I fixed it in the cmake files of the samples but I am wondering if you forgot to put pthread library in all of your cmakelists files or this is an installation or a dependency problem ?