anchor.diff:  }:
   
   let
  -  inherit (stdenv.lib)
  +  inherit (lib)
       boolWt
       optionals
       optionalString;
   
  -  channel = "1.50";
  +  channel = "1.52";
     version = "${channel}.0";
   in
   stdenv.mkDerivation rec {
  
positive.code:   src = fetchurl {
      url = "mirror://gnome/sources/gobject-introspection/${channel}/${name}.tar.xz";
      hashOutput = false;
      sha256 = "1c6597c666f543c70ef3d7c893ab052968afae620efdc080c36657f4226337c5";
    };
  
    nativeBuildInputs = [
  
negative.code:     })
    ];
  
    postPatch = /* patchShebangs does not catch @PYTHON@ */ ''
      sed -i tools/g-ir-tool-template.in \
        -e 's|#!/usr/bin/env @PYTHON@|#!${python2.interpreter}|'
    '' +
  