[ 50%] Linking CXX executable Learning
Undefined symbols for architecture x86_64:
  "_randombytes_random", referenced from:
      _main in main.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [Learning] Error 1
make[2]: *** [CMakeFiles/Learning.dir/all] Error 2
make[1]: *** [CMakeFiles/Learning.dir/rule] Error 2
make: *** [Learning] Error 2