brazil.nix

{ mkDerivation, aeson, aeson-pretty, base, blaze-html, bytestring
, data-default, either, free, lens, optparse-applicative
, QuickCheck, semigroups, stdenv, system-filepath, tasty
, tasty-hunit, tasty-quickcheck, text, text1, time, url
, xml-conduit, xml-conduit-decode
}:
mkDerivation {
  pname = "brazil";
  version = "0.1.0.0";
  src = ./.;
  isLibrary = true;
  isExecutable = true;
  libraryHaskellDepends = [
    aeson aeson-pretty base blaze-html bytestring data-default either
    free lens optparse-applicative semigroups text text1 time url
    xml-conduit xml-conduit-decode
  ];
  executableHaskellDepends = [
    aeson aeson-pretty base blaze-html bytestring data-default either
    free lens optparse-applicative semigroups text text1 url
    xml-conduit xml-conduit-decode
  ];
  testHaskellDepends = [
    base data-default lens QuickCheck semigroups system-filepath tasty
    tasty-hunit tasty-quickcheck text text1 url xml-conduit
    xml-conduit-decode
  ];
  license = stdenv.lib.licenses.unfree;
}

default.nix

{}:

let
  nixpkgs = import ./nixpin.nix { };

  sources = {
    text1 = nixpkgs.fetchFromGitHub {
      owner = "qfpl";
      repo = "tex1";
      rev = "1b383775f706f2a0d38b793a34c9eb5fea2e77d1";
      sha256 = "01h44a9hkb5ki8b4yds8q5qbjy6mypjhfkgvrhwhxjq541wfx6lw"; # this sha is wrong
      fetchSubmodules = true;
    };
  };

  modifiedHaskellPackages = nixpkgs.haskellPackages.override {
    overrides = self: super: {
      xml-conduit-decode = nixpkgs.haskell.lib.dontCheck super.xml-conduit-decode;
      text1 = import sources.text1 { inherit nixpkgs; };
    };
  };

  _brazil = modifiedHaskellPackages.callPackage ./brazil.nix { };

in {
  brazil = _brazil;
}

nixpin.nix

import (fetchTarball {
    url = "https://github.com/NixOS/nixpkgs-channels/archive/8b1cf100cd8badad6e1b6d4650b904b88aa870db.tar.gz";
    # Wait till new nix version is released.
    #sha256 = "16lypr390jcl18d174z6ih732phbpqp40pjq06gsisnm04b6bl1z";
  }
)

shell.nix

let
  nixpkgs   = import ./nixpin.nix {};
  brazil' = (import ./. {}).brazil;
  brazil  = nixpkgs.haskell.lib.addBuildDepends brazil' (with nixpkgs.haskellPackages;
    [ cabal-install cabal2nix hindent hasktags hlint apply-refact ghcid ]
  );
in brazil.env

update_nixpin.sh

#!/usr/bin/env nix-shell
#!nix-shell -i bash -p bash nix curl jq
#
# Updates the nixpin.nix to the latest channel release
# From https://gist.github.com/zimbatm/de5350245874361762b6a4dfe5366530
set -euo pipefail

cd "$(dirname "$0")" || exit 1

branch=nixos-unstable

owner=NixOS
repo=nixpkgs-channels
rev=$(curl -sfL https://api.github.com/repos/$owner/$repo/git/refs/heads/$branch | jq -r .object.sha)
url=https://github.com/$owner/$repo/archive/$rev.tar.gz

release_sha256=$(nix-prefetch-url "$url")

cat <<NIXPKGS | tee nixpin.nix
import (fetchTarball {
    url = "$url";
    # Wait till new nix version is released.
    #sha256 = "$release_sha256";
  }
)
NIXPKGS