haskellPackages.hakyll project problem

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1

Hi there,

I’m fairly new to nix so bear with me. I try to build a general derivation to build a static page via hakyll. So far so good, this is my state:

When running nix-build there is brings up an error:

Compiling
  [ERROR] Hakyll.Core.Compiler.Require.load: templates/archive.html (snapshot _final) was not found in the cache, the cache might be corrupted or the item you are referring to might not exist

I guess there is a problem with the nix stages I currently don’t understand.

Some background how this logic should work:

  • build the haskell hakyll binary which builds the static page from the templates and so on (its a buildInput then)
  • execute the binary to actually generate the static page

but now there the actual problem:

hakyll uses a _cache directory for intermediate build output. My assumption is the produced binary site does not place the binary in a writable location.

What would be the ideal world nix solution to solve this? I’m calling a binary which produces “riot” some output to _cache and _site . How to redirect this without customizing the binary?

Greetings

Jan

2

Hey Jan,

welcome to this forum.

At first glance I’m unable to find the cause for your build failure, but I can show you my working setup for hakyll:

# file default.nix
# Some code copied and/or modified from
# https://utdemir.com/posts/hakyll-on-nixos.html
{stdenv, ghcWithPackages, glibcLocales}:
let
  generator = stdenv.mkDerivation {
    name = "example.org-generator";
    src = ./generator;
    phases = "unpackPhase buildPhase";
    buildInputs = [
      (ghcWithPackages (p: with p; [ hakyll ]))
    ];
    buildPhase = ''
      mkdir -p $out/bin
      ghc -O2 -dynamic --make site.hs -o $out/bin/generate-site
    '';
  };
in
stdenv.mkDerivation rec {
  name = "example.org";
  src = ./.;
  phases = "unpackPhase buildPhase";
  buildInputs = [ generator ];

  LOCALE_ARCHIVE = "${glibcLocales}/lib/locale/locale-archive";
  LANG = "en_US.UTF-8";

  buildPhase = ''
    generate-site --verbose build

    echo Copying
    mkdir -p $out
    cp -r _site/* $out
  '';
  meta = {
    license = stdenv.lib.licenses.free;
  };
}

# file release.nix
let
  pkgs = import <nixpkgs> {};
  stdenv = pkgs.stdenv;
  glibcLocales = pkgs.glibcLocales;
in
{
  public = import ./default.nix {
    inherit stdenv glibcLocales;
    inherit (pkgs.haskellPackages) ghcWithPackages;
  };
}

To build: nix build -f release.nix. My site.hs resides in ./generator/site.hs.

Good luck!

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3

Thanks for your insight. Helped alot! I switched from having a builder script for calling the generator binary to the inline buildPhase script and somehow it worked.

My working solution can be found here at this commit: GitHub - MaxDaten/brutal-recipes at 10fecbe2a1fe70da37ce1c59caaebda9695984bd

2 Likes