nixpkgs-update/flake.nix

{
  description = "A flake for nixpkgs-update";

  inputs.flake-utils.url = "github:numtide/flake-utils";
  inputs.nixpkgs-review.url = "github:mic92/nixpkgs-review";
  inputs.flake-compat = { url = "github:edolstra/flake-compat"; flake = false; };
  inputs.nixpkgs = { type = "github"; owner = "nixos"; repo = "nixpkgs"; };

  outputs = { self, flake-utils, flake-compat, nixpkgs, nixpkgs-review }:
    flake-utils.lib.eachSystem ["x86_64-linux"] (system:
      let
        pkgs = import nixpkgs { inherit system; config = { allowBroken = true; }; };

        developPackageAttrs = {
          name = "nixpkgs-update";
          root = self;
          returnShellEnv = false;
        };

        drvAttrs = attrs: with pkgs; {
          # TODO: lock down coreutils paths too
          NIX = nix;
          GIT = git;
          HUB = gitAndTools.hub;
          JQ = jq;
          TREE = tree;
          GIST = gist;
          NIXPKGSREVIEW = (import nixpkgs-review { inherit pkgs; });
        };

        haskellPackages = pkgs.haskell.packages.ghc8102.override {
          overrides = _: haskellPackages: {
            nixpkgs-update =
              pkgs.haskell.lib.justStaticExecutables (
                pkgs.haskell.lib.failOnAllWarnings (
                  pkgs.haskell.lib.disableExecutableProfiling (
                    pkgs.haskell.lib.disableLibraryProfiling (
                      pkgs.haskell.lib.generateOptparseApplicativeCompletion "nixpkgs-update" (
                        (haskellPackages.developPackage developPackageAttrs).overrideAttrs drvAttrs
                      )
                    )
                  )
                )
              );
          };
        };

        shell = haskellPackages.shellFor {
          nativeBuildInputs = with pkgs; [
            cabal-install
            ghcid
          ];
          packages = ps: [ ps.nixpkgs-update ];
          shellHook = ''
          '';
        };

      in {
        devShell = shell;
        packages.nixpkgs-update = haskellPackages.nixpkgs-update;
        defaultPackage = haskellPackages.nixpkgs-update;
      });
}