self: super:

let

    src = {
        codex = super.fetchFromGitHub {
            owner = "aloiscochard";
            repo = "codex";
            rev = "48b2a4b94132b537943bcd966c3922cbf67a7409";
            sha256 = "1mwsz824rqsphy68frqdrpkdmvlqg3zfn7wb565r8621jbbn9iws";
        };
        haskell-code-explorer = super.fetchFromGitHub {
            owner = "alexwl";
            repo = "haskell-code-explorer";
            #rev = "eddf2c825dee199de0e958857f0daf3d08a07532";
            #rev = "cac568f01609bf224c0e26ec62880bf7dbb58a07";
            rev = "3da88457b2566aec3f4e0b368a21c9f2bb389e29";
            #sha256 = "07b8apl6qkp3bahjyykhskrsfwbglc69dpr43lifbc8pg0xv1v49";
            #sha256 = "0s26yav6w4j4nzrbdv3wms931zbi0vm2nbiinfqwv87x35y42sbg";
            sha256 = "0yib189bh9x5qs5rx4a7i3cj77nn7nd6395kdm1nb2120iv37bl5";
        };
    };

    ghc82Packages = super.haskell.packages.ghc822.override {
        overrides = hSelf: hSuper: {
        };
    };

    ghc84Packages = super.haskell.packages.ghc844.override {
        overrides = hSelf: hSuper: {
        };
    };

    ghc86Packages = super.haskell.packages.ghc865.override {
        overrides = hSelf: hSuper: {
        };
    };

    haskellPackages = super.haskellPackages.override {
        overrides = hSelf: hSuper: {

            # DESIGN: pinning to the latest version
            codex = hSuper.callCabal2nix "codex" src.codex {};
            haskell-code-explorer = hSuper.callCabal2nix "haskell-code-explorer" src.haskell-code-explorer {};

            # DESIGN: try commenting out, but the tests hang
            #ghc-exactprint = super.haskell.lib.dontCheck (hSuper.callHackage "ghc-exactprint" "0.5.8.2" {});
            ghc-exactprint = super.haskell.lib.dontCheck (hSuper.callHackage "ghc-exactprint" "0.6.1" {});

            # DESIGN: Nixpkgs isn't on latest yet (as of 2019-04-30), but this # breaks
            # hlint = hSuper.callHackage "hlint" "2.1.17" {};

            #ghcid = hSuper.callHackage "hlint" "0.7.2" {};

            # Not using currently
            #cabal-helper = super.haskell.lib.doJailbreak hSuper.cabal-helper;
            #cabal-helper = hSuper.callHackage "cabal-helper" "0.8.2.0" {};
        };
    };

    haskellApp = super.haskell.lib.justStaticExecutables;

    # fails to build
    nodejs =
        let buildNodejs = super.callPackage
                "${super.path}/pkgs/development/web/nodejs/nodejs.nix" {};
            enableNpm = true;
            rawNodejs = buildNodejs {
                inherit enableNpm;
                version = "10.15.1";
                sha256 = "0n68c4zjakdj6yzdc9fbrn0wghyslkya9sz1v6122i40zfwzfm8s";
            };
            rawNodejs_ = super.callPackage
                "${super.path}/pkgs/development/web/nodejs/v10.nix" {};
        in super.lib.hiPrio rawNodejs;

    yarn = self.yarn.override { nodejs = self.nodejs-10_x; };

in

{

    global = super.global.overrideAttrs (oldAttrs: {
        postInstall = ''
          mkdir -p "$out/share/emacs/site-lisp"
          cp -v *.el "$out/share/emacs/site-lisp"

          wrapProgram $out/bin/gtags \
            --set GTAGSCONF "$out/share/gtags/gtags.conf" \
            --prefix PYTHONPATH : "$(toPythonPath ${super.pythonPackages.pygments})"
          wrapProgram $out/bin/global \
            --set GTAGSCONF "$out/share/gtags/gtags.conf" \
            --prefix PYTHONPATH : "$(toPythonPath ${super.pythonPackages.pygments})"
        '';
    });

    all-cabal-hashes = super.fetchurl {
        url = "https://github.com/commercialhaskell/all-cabal-hashes/archive/58e8d9489a7588093b432bcdc9a981628e41673a.tar.gz";
        sha256 = "1qwq386q15pwwy8136n632hzy0gkrmi57gfdyz7lh5nixcrmdhmi";
    };

    my-packages = [
        yarn
        self.autojump
        self.cabal-install
        self.cabal2nix
        self.cloc
        self.coreutils
        self.dfu-programmer
        self.dfu-util
        self.dhall
        self.direnv
        self.fswatch
        self.ghc
        self.git
        self.global
        self.gnugrep
        self.gnupg
        self.graphviz
        self.htop
        self.imagemagick
        self.ispell
        self.jq
        self.jre
        self.kubernetes-helm
        self.mpc_cli
        self.mongodb
        self.mongodb-tools
        self.nix-diff
        self.nix-index
        self.nodejs
        self.oh-my-zsh
        self.pandoc
        self.patchelf
        self.postgresql
        self.procps
        self.ripgrep
        self.rsync
        self.sbt-extras
        self.schemaspy
        self.shellcheck
        self.silver-searcher
        self.stack
        self.stack2nix
        self.teensy-loader-cli
        self.tree
        self.unison
        self.unzip
        self.vim
        self.wget
        self.yarn2nix
        (haskellApp haskellPackages.apply-refact)
        (haskellApp haskellPackages.codex)
        (haskellApp haskellPackages.fast-tags)
        (haskellApp haskellPackages.ghc-events)
        (haskellApp haskellPackages.ghcid)
        (haskellApp haskellPackages.haskdogs)
        (haskellApp haskellPackages.hasktags)
        (haskellApp haskellPackages.hlint)
        (haskellApp haskellPackages.hoogle)
        (haskellApp haskellPackages.hp2pretty)
        (haskellApp haskellPackages.hpack)
        (haskellApp haskellPackages.pointfree)
        (haskellApp haskellPackages.stylish-haskell)
        #self.emacs                                         # emacs-mac from Brew more compatible with Mac/Yabai
        #(haskellApp ghc82Packages.djinn)                   # interesting, but exotic
        #(haskellApp haskellPackages.ghc-events-analyze)    # replacement?
        #(haskellApp haskellPackages.haskell-code-explorer) # finicky build
        #(haskellApp haskellPackages.pointful)              # interesting, but exotic
        #(haskellApp haskellPackages.purescript)            # finicky build
        #(haskellApp haskellPackages.threadscope)           # broken on Darwin
        #self.nodePackages_8_x.npm                          # finicky build
    ];

}