anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "libmodulemd";
  -  version = "2.9.2";
  +  version = "2.12.0";
   
     outputs = [ "bin" "out" "dev" "devdoc" "man" "py" ];
   
  
positive.code: { lib, stdenv
  , substituteAll
  , fetchFromGitHub
  , fetchpatch
  , pkg-config
  , meson
  , ninja
  
negative.code:     (substituteAll {
        src = ./glib-devdoc.patch;
        glib_devdoc = glib.devdoc;
      })
    ];
  
  