fix: entire build

flake.nix

@@ -1,48 +1,93 @@
 {
   description = "hakyll-nix-template";
 
-  nixConfig.bash-prompt = "[nix]λ ";
-
-  inputs = {
-    nixpkgs.url = "nixpkgs/nixos-21.05";
-
-    flake-utils = {
-      url = "github:numtide/flake-utils";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
+  nixConfig = {
+    allow-import-from-derivation = "true";
+    bash-prompt = "[nix]λ ";
+    extra-substituters = [
+      "https://cache.iog.io"
+      "https://cache.zw3rk.com" # https://github.com/input-output-hk/haskell.nix/issues/1408
+    ];
+    extra-trusted-public-keys = [
+      "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ="
+      "loony-tools:pr9m4BkM/5/eSTZlkQyRt57Jz7OMBxNSUiMC4FkcNfk="
+    ];
   };
 
-  outputs = { flake-utils, nixpkgs, self }:
+  inputs.haskellNix.url = "github:input-output-hk/haskell.nix";
+  inputs.nixpkgs.follows = "haskellNix/nixpkgs-unstable";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils, haskellNix }:
     flake-utils.lib.eachDefaultSystem (system:
       let
-        config = {};
-        overlays = [ (import ./haskell-overlay.nix) ];
-        pkgs = import nixpkgs { inherit config overlays system; };
-      in rec {
-        defaultPackage = packages.website;
+        overlays = [ haskellNix.overlay
+          (final: prev: {
+            bobProject = final.haskell-nix.project' {
+              src = ./ssg;
+              compiler-nix-name = "ghc925";
+              shell.buildInputs = [
+                hakyll-site
+              ];
+              shell.tools = {
+                cabal = "latest";
+                hlint = "latest";
+                haskell-language-server = "latest";
+              };
+            };
+          })
+        ];
 
-        packages = with pkgs.myHaskellPackages; { inherit ssg website; };
-
-        apps.default = flake-utils.lib.mkApp {
-          drv = packages.ssg;
-          exePath = "/bin/hakyll-site";
+        pkgs = import nixpkgs {
+          inherit overlays system;
+          inherit (haskellNix) config;
         };
 
-        devShell = pkgs.myHaskellPackages.shellFor {
-          packages = p: [ p.ssg ];
+        flake = pkgs.bobProject.flake {};
 
-          buildInputs = with pkgs.myHaskellPackages; [
-            ssg
+        executable = "ssg:exe:hakyll-site";
 
-            # Helpful tools for `nix develop` shells
-            #
-            #ghcid                   # https://github.com/ndmitchell/ghcid
-            #haskell-language-server # https://github.com/haskell/haskell-language-server
-            #hlint                   # https://github.com/ndmitchell/hlint
-            #ormolu                  # https://github.com/tweag/ormolu
-          ];
+        hakyll-site = flake.packages.${executable};
 
-          withHoogle = true;
+        website = pkgs.stdenv.mkDerivation {
+          name = "website";
+          buildInputs = [];
+          src = pkgs.nix-gitignore.gitignoreSourcePure [
+            ./.gitignore
+            ".git"
+            ".github"
+          ] ./.;
+
+          # LANG and LOCALE_ARCHIVE are fixes pulled from the community:
+          #   https://github.com/jaspervdj/hakyll/issues/614#issuecomment-411520691
+          #   https://github.com/NixOS/nix/issues/318#issuecomment-52986702
+          #   https://github.com/MaxDaten/brutal-recipes/blob/source/default.nix#L24
+          LANG = "en_US.UTF-8";
+          LOCALE_ARCHIVE = pkgs.lib.optionalString
+            (pkgs.buildPlatform.libc == "glibc")
+            "${pkgs.glibcLocales}/lib/locale/locale-archive";
+
+          buildPhase = ''
+            ${flake.packages.${executable}}/bin/hakyll-site build --verbose
+          '';
+
+          installPhase = ''
+            mkdir -p "$out/dist"
+            cp -r dist/* "$out/dist"
+          '';
+        };
+
+      in flake // rec {
+        apps = {
+          default = flake-utils.lib.mkApp {
+            drv = hakyll-site;
+            exePath = "/bin/hakyll-site";
+          };
+        };
+
+        packages = {
+          inherit hakyll-site website;
+          default = website;
         };
       }
     );