anchor.diff:      pkg-config
       python3
       wrapGAppsHook
  +    gi-docgen
       xorgserver # for cvt command
     ];
   
  
positive.code: , xorgserver
  , python3
  , wrapGAppsHook
  , sysprof
  , libsysprof-capture
  , desktop-file-utils
  
negative.code:   pname = "mutter";
    version = "43.beta";
  
    outputs = [ "out" "dev" "man" "devdoc" ];
  
    src = fetchurl {
      url = "mirror://gnome/sources/mutter/${lib.versions.major version}/${pname}-${version}.tar.xz";
  