Less lazy packaging

flake.nix

@@ -1,9 +1,4 @@
-# SPDX-FileCopyrightText: 2021 Serokell <https://serokell.io/>
-#
-# SPDX-License-Identifier: CC0-1.0
-
-{
-  description = "generate a index of gemtext files";
+{ description = "generate a index of gemtext files";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs";
@@ -15,30 +10,8 @@
       let
         pkgs = nixpkgs.legacyPackages.${system};
 
-        haskellPackages = pkgs.haskellPackages;
-
-        jailbreakUnbreak = pkg:
-          pkgs.haskell.lib.doJailbreak (pkg.overrideAttrs (_: { meta = { }; }));
-
-        # DON'T FORGET TO PUT YOUR PACKAGE NAME HERE, REMOVING `throw`
-        packageName = "twin";
+        compiler = "ghc94";
       in {
-        packages.${packageName} =
-          haskellPackages.callCabal2nix packageName self rec {
-            # Dependency overrides go here
-          };
-
-        packages.default = self.packages.${system}.${packageName};
-        defaultPackage = self.packages.${system}.default;
-
-        devShells.default = pkgs.mkShell {
-          buildInputs = with pkgs; [
-            haskellPackages.haskell-language-server # you must build it with your ghc to work
-            ghcid
-            cabal-install
-          ];
-          inputsFrom = map (__getAttr "env") (__attrValues self.packages.${system});
-        };
-        devShell = self.devShells.${system}.default;
+        packages.default = pkgs.haskell.packages.${compiler}.callPackage ./package.nix { };
       });
 }

package.nix

@@ -0,0 +1,11 @@
+{ mkDerivation, base, directory, lib, optparse-applicative }:
+mkDerivation {
+  pname = "twin";
+  version = "0.1.0.0";
+  src = ./.;
+  isLibrary = false;
+  isExecutable = true;
+  executableHaskellDepends = [ base directory optparse-applicative ];
+  license = lib.licenses.agpl3Plus;
+  mainProgram = "twin";
+}