{ stdenv ? (import <nixpkgs> {}).stdenv
, haskellPackages ? (import <nixpkgs> {}).haskellPackages
}:

let
  override = stdenv.lib.overrideDerivation;
  callPackage = haskellPackages.callPackage;
  tprint = callPackage ./thermoprint/tprint/tprint.nix {
    inherit thermoprint-servant thermoprint bbcode;
  };
  bbcode = callPackage ./thermoprint/bbcode/bbcode.nix {
    inherit thermoprint;
  };
  thermoprint-servant = callPackage ./thermoprint/servant/servant.nix {
    inherit thermoprint;
  };
  thermoprint = callPackage ./thermoprint/thermoprint/thermoprint.nix {};
in rec {
  tprint = override tprint (oldAttrs: { src = ./thermoprint/tprint; });
  bbcode = override bbcode (oldAttrs: { src = ./thermoprint/bbcode; });
  thermoprint-servant = override thermoprint-servant (oldAttrs: { src = ./thermoprint/servant; });
  thermoprint = override thermoprint (oldAttrs: { src = ./thermoprint/thermoprint; });
}