Environment Setup

I would like to share my development environment setup before we started the journey. I use nix-shell along with direnv to setup the development environment.

For nix, please checkout the Nix Pills for more details.

Install the direnv package. In the project root, create shell.nix, this would define a nix-shell:

{ pkgs ? import <nixpkgs> {} }:

let
  llvmPkgs = pkgs.llvmPackages_latest;
in
pkgs.mkShell {
  buildInputs = [
    llvmPkgs.llvm.dev
    llvmPkgs.clang
    llvmPkgs.bintools

    pkgs.cmake
    pkgs.pkg-config
    pkgs.flex
    pkgs.zlib
    pkgs.libffi
  ];

  # ponytail: nix zlib paths so cmake's find_package resolves ZLIB::ZLIB for LLVM
  shellHook = ''
    export ZLIB_ROOT="${pkgs.zlib.dev}"
    export LIBCLANG_PATH="${llvmPkgs.libclang.lib}/lib"
    echo "Entering C++ development environment"
  '';
}

It would install the clang toolchain, llvm headers and libraries, flex, zlib, and libffi libraries, and export the environment variables for discovery.

Then in the .envrc, simply add

use nix

this would instruct direnv to load nix-shell defined in shell.nix.

Enable direnv as direnv allow ., the nix-shell will populate the dev environment. Once you change the directory, this environment is unloaded automatically. Quite neat.