{
  esbuild,
  stdenv,
  elmPackages,
  ...
}: let
  elmConfig = elmPackages.fetchElmDeps {
    elmPackages = import ./frontend/elm-srcs.nix;
    elmVersion = "0.19.1";
    registryDat = ./frontend/registry.dat;
  };
in
  stdenv.mkDerivation {
    pname = "elmskell-backend";
    version = "0.1.0";
    src = ./frontend;
    nativeBuildInputs = [
      esbuild
      elmPackages.elm
    ];
    buildInputs = [
    ];
    configurePhase = ''
      ${elmConfig}
    '';
    buildPhase = ''
      elm make src/Main.elm --optimize --output=tmp.js
      esbuild tmp.js --minify --target=es5 --outfile=main.js
    '';
    installPhase = ''
      mkdir -p $out
      cp main.js $out/main.js
    '';
  }