You will need to install llvm. instructions can be found here
You might need to modify the location of your llvm project in the root directory of the CMakeLists.txt file
set(LLVM_DIR /opt/homebrew/opt/llvm/lib/cmake/llvm)
The one above works for macOS systems if you're installed it using homebrew. As long as you install llvm in a standard file location, this shouldn't be a problem.
git submodule update --init --recursive
cmake -S . -B cmake-build-debug
cmake --build cmake-build-debug -j 12
ctest --test-dir cmake-build-debug --output-on-failure