{
  description = "Post-ERG development environment";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};

        php = pkgs.php84.buildEnv {
          extensions = ({ enabled, all }: enabled ++ (with all; [
            curl
            mbstring
            pdo
            pdo_sqlite
            sqlite3
          ]));
          extraConfig = ''
            error_reporting = E_ALL
            display_errors = On
            log_errors = On
          '';
        };
      in
      {
        devShells.default = pkgs.mkShell {
          name = "posterg";

          packages = [
            php
            pkgs.sqlite
            pkgs.just
            pkgs.git
          ];

          shellHook = ''
            echo "🛠  Post-ERG dev shell"
            echo "  php   $(php --version | head -1)"
            echo "  just  $(just --version)"
            echo ""
            echo "Run 'just serve' to start the dev server."
          '';
        };
      });
}