haskell-flake.nix

{
  description = "PandocProject";
  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.eachSystem [ "x86_64-linux" ] (system:
    let
      overlays = [ haskellNix.overlay
        (final: prev: {
          # This overlay adds our project to pkgs
          pandocProject = final.haskell-nix.cabalProject {
              cabalProjectFreeze = null;
              cabalProject = null;
              cabalProjectLocal = null;

              compiler-nix-name = "ghc8104";
              name = "pandocProject";

              src = final.fetchFromGitHub {
                 name = "pandoc";
                 owner = "jgm";
                 repo = "pandoc";
                 rev = "d05460d00d7c9af3b4913f1760ea385a7d855d84";
                 sha256 = "1a3kwag6j13b42zhzxiwlzabsc6c9jppiwv9j8gbnf2k1yb84kdm";
              };

              pkg-def-extras = with final.haskell.lib; [];
            };
        })
      ];
      pkgs = import nixpkgs { inherit system overlays; };
      flake = pkgs.pandocProject.flake {};
    in flake // {
      # Built by `nix build .`
      inherit overlays;
      defaultPackage = flake.packages."pandoc:exe:pandoc";
    });
}

mixed-two-flakes.nix

{
  description = "MixedFlake";
  inputs.flake-utils.url = "github:numtide/flake-utils";
  inputs.wiki-python.url = "git+https://gitlab.huma-num.fr/gt-notebook/wiki.git?ref=main";
  inputs.wiki-pandoc.url = "git+https://gitlab.huma-num.fr/gt-notebook/nix/pandoc-2-14-02.git?ref=main";

  outputs = { self, nixpkgs, flake-utils, wiki-python, wiki-pandoc }:
      let
      my-overlay = nixpkgs.lib.composeManyExtensions [
      wiki-python.overlay 
      wiki-pandoc.overlays
      ];

      pkgsForSystem = system:
        (import nixpkgs) {
          inherit system;
          overlays = [
            my-overlay
          ];
      };

      in (flake-utils.lib.eachSystem ["x86_64-linux"] (system: rec {

      pkgs = pkgsForSystem system;
      legacyPackages = pkgs;

      packages = flake-utils.lib.flattenTree {
        inherit (legacyPackages)
        wikiApp;
        };

      defaultPackage = legacyPackages;

        /*
        devShell = legacyPackages.mkShell {
          packages = [
            packages.pandocProject
            packages.wikiApp
          ];
        };*/

        /*apps = { pandocProject }: {
          pandoc = flake-utils.lib.mkApp { drv = pandocProject; };
          defaultApp = flake-utils.lib.mkApp { drv = pandocProject; };
        };*/

    }));
    }

poetry2nix-flake.nix

{
  description = "Application packaged using poetry2nix";

  inputs = {
    flake-utils.url = "github:numtide/flake-utils";
    nixpkgs.url = "github:NixOS/nixpkgs";
    poetry.url = "github:nix-community/poetry2nix";
    };

  outputs = inputs@{ self, nixpkgs, flake-utils, poetry }:
    let overlay = final: prev: ({
        wikiApp = final.poetry2nix.mkPoetryApplication {
          projectDir = ./.;
          python = prev.python39;
          propagatedBuildInputs = [
            prev.graphviz
            prev.bash
            prev.wget
            prev.findutils
          ];
        };
    } //
    (poetry.overlay final prev));
    in
    flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
      let
        pkgs = import nixpkgs { inherit system; overlays = [ overlay]; };
      in  {
        defaultPackage =  pkgs.wikiApp;
        }) // {
      inherit overlay;
    };
}