Use this to easily build your hakyll websites using nix flakes.

hakyll-flakes.lib.mk* takes in a set with the following fields:

• system: the system to build for.
• name: the name of website. this must also be the name of the haskell project and executable generated.
• src: the source directory (usually ./.), which must contain at a minimum your package.yaml or project-name.cabal file.
• websiteBuildInputs (optional): any runtime inputs the builder needs to build the website.

hakyll-flakes.overlay is the overlay that hakyll-flakes uses internally to get hakyll working (this will not work on an arbitrary version of nixpkgs), and hakyll-flake.pkgs is the legacyPackages that hakyll-flakes uses internally (this should always work). If you want to use one consistent nixpkgs set, you can set websiteBuildInputs = with hakyll-flakes.pkgs.${system}; [ ... ]. Alternatively, you can use your own nixpkgs set for these inputs, there's no reason they need to be the same.

{
  description = "My Website";
  inputs.nixpkgs.url = "github:nixos/nixpkgs";
  inputs.hakyll-flakes.url = "github:Radvendii/hakyll-flakes";
  inputs.flake-utils.url = "github:numtide/flake-utils";

  outputs = { self, hakyll-flakes, flake-utils, nixpkgs }:
    flake-utils.lib.eachDefaultSystem (
      system:
      hakyll-flakes.lib.mkAllOutputs {
        inherit system;
        name = "my-website";
        src = ./.;
        websiteBuildInputs = with nixpkgs.legacyPackages.${system}; [
          rubber
          texlive.combined.scheme-full
          poppler_utils
        ];
      }
    );
}

name: my-website

dependencies:
    - base
    - hakyll
    - filepath
    - pandoc
    - containers
    - time
    - pandoc-types
    - hakyll-sass
    - process
    - bytestring
    - uri-encode
    - text
    - time-locale-compat

executable:
    main: site.hs

Then from the top level directory you can run a few different commands:

• nix build .#website (or just nix build) this goes through the whole process for you and simply produces a result/ symlink with your compiled website inside.
• nix build .#builder this builds the website builder, your hakyll-based site.hs file. You can find it at result/bin/<project name>.
• nix run . -- watch This will compile and run your website builder, creating the _site directory and loading the website at localhost:8000. It will also rebuild the website if you change the files (but not if you change site.hs)

You can pick out the individual outputs you want with mkBuilderPackage, mkWebsitePackage, mkDevShell, and mkApp.