anchor.diff:      owner = "upower";
       repo = "upower";
       rev = "v${version}";
  -    sha256 = "xvvqzGxgkuGcvnO12jnLURNJUoSlnMw2g/mnII+i6Bs=";
  +    sha256 = "gpLsBh4jgiDO8bxic2BTFhjIwc2q/tuAIxykTHqK6UM=";
     };
   
     strictDeps = true;
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "upower";
    version = "0.99.17";
  
    outputs = [ "out" "dev" ]
      ++ lib.optionals withDocs [ "devdoc" ];
  
negative.code:     "-Dos_backend=linux"
      "-Dsystemdsystemunitdir=${placeholder "out"}/etc/systemd/system"
      "-Dudevrulesdir=${placeholder "out"}/lib/udev/rules.d"
      "-Dudevhwdbdir=${placeholder "out"}/lib/udev/hwdb.d"
      "-Dintrospection=${if (stdenv.buildPlatform == stdenv.hostPlatform) then "auto" else "disabled"}"
      "-Dgtk-doc=${lib.boolToString withDocs}"
    ];
  