How to build the latest clang-tidy?

Up-to-date steps:

git clone https://github.com/llvm/llvm-project.git
cd llvm-project
mkdir build 
cd build
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra" ../llvm
make install clang-tidy

Reference, ninja, and other details: my own blog post.