flake.nix

{
  inputs = {
    nixpkgs.url = github:nixos/nixpkgs/nixpkgs-unstable;
    flake-utils.url = github:numtide/flake-utils;
    nix-filter.url = github:numtide/nix-filter;
    language-c = {
      url = github:kalhauge/language-c;
      flake = false;
    };
    hspec-glitter.url = github:kalhauge/hspec-glitter;
  };
  outputs = {
    self,
    nixpkgs,
    flake-utils,
    nix-filter,
    ...
  } @ inputs: let
    load = p: n:
      p.callCabal2nixWithOptions n (nix-filter.lib {root = "${self}/${n}";}) "" {};

    packages = lib: p: {
      "language-c" = lib.dontCheck (p.callCabal2nixWithOptions "language-c" inputs.language-c "" {});
      "hspec-glitter" = p.callCabal2nixWithOptions "hspec-glitter" inputs.hspec-glitter "" {};
      "rtree" = lib.dontCheck (load p "rtree");
      "rtree-c" = lib.dontCheck (load p "rtree-c");
    };
  in
    flake-utils.lib.eachDefaultSystem
    (system: let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [];
      };
      lib = pkgs.haskell.lib;
      hpkgs = pkgs.haskellPackages.override (hpArgs: {
        overrides = pkgs.lib.composeExtensions (hpArgs.overrides or (_: _: {})) (
          _hfinal: hprev: packages lib hprev
        );
      });
    in {
      packages = {
        default = lib.justStaticExecutables (hpkgs.rtree-c);
        rtree = hpkgs.rtree;
        rtree-c = hpkgs.rtree-c;
      };
      devShells = let
        nativeBuildInputs = with hpkgs; [
          cabal-install
          ghcid
          haskell-language-server
          hpack
          fourmolu
        ];
        withHoogle = true;
        profiles = hpkgs.override (hpArgs: {
          overrides = pkgs.lib.composeExtensions (hpArgs.overrides or (_: _: {})) (
            _hfinal: hprev: {
              mkDerivation = args:
                hprev.mkDerivation ({
                    doCheck = false;
                    doBenchmark = false;
                    doHoogle = true;
                    doHaddock = true;
                    enableLibraryProfiling = true;
                    enableExecutableProfiling = true;
                  }
                  // args);
              aeson = hprev.aeson.override {
                mkDerivation = args: