anchor.diff:  
   let
     inherit (lib)
  -    boolEn
  +    boolYn
       optionals;
   
     sources = {
  
positive.code: { stdenv
  , fetchurl
  , lib
  , python3
  , yasm
  
  , glib
  , gst-plugins-bad
  
negative.code:   };
  
    nativeBuildInputs = [
      meson
      ninja
    ];
  
    buildInputs = [
  