{
  description = "Lucy prime counting sieve";
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

  outputs = { self, nixpkgs }: let
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.${system};
  in {
    packages.${system}.default = pkgs.stdenv.mkDerivation {
      pname = "lucy";
      version = "1.0";
      src = ./.;

      buildInputs = [ pkgs.glibc ];

      buildPhase = ''
        gcc -O2 -o lucy main.c -lm
      '';

      installPhase = ''
        mkdir -p $out/bin
        cp lucy $out/bin/lucy
      '';
    };

    devShells.${system}.default = pkgs.mkShell {
      packages = [ pkgs.gcc pkgs.gdb pkgs.valgrind ];
    };
  };
}