anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "gnome-system-monitor";
  -  version = "42.alpha";
  +  version = "42.rc";
   
     src = fetchurl {
       url = "mirror://gnome/sources/gnome-system-monitor/${lib.versions.major version}/${pname}-${version}.tar.xz";
  -    sha256 = "puK3mIgkm/YQpVaOCvjq2gFNiQ1PwXxWb2Gk21lHqMo=";
  +    sha256 = "CfScgbZZVvHW3ZnumpQRJkvzSPRRbIu6m6sLX/x8D0c=";
     };
   
     nativeBuildInputs = [
  
positive.code:     wrapGAppsHook
      meson
      ninja
      python3
    ];
  
    buildInputs = [
  
negative.code: , wrapGAppsHook
  , meson
  , ninja
  , gsettings-desktop-schemas
  , itstool
  , gnome
  