anchor.diff:  
   let
     inherit (stdenv.lib)
  -    enFlag
  -    optionalString
  -    wtFlag;
  +    boolEn
  +    boolString
  +    boolWt;
   in
   stdenv.mkDerivation rec {
     name = "libgpod-0.8.3";
   
     src = fetchurl {
       url = "mirror://sourceforge/gtkpod/${name}.tar.bz2";
  -    sha256 = "0pcmgv1ra0ymv73mlj4qxzgyir026z9jpl5s5bkg35afs1cpk2k3";
  +    multihash = "QmQHafZSqYSAdTqbNqjFLdo9zhcAP4URDbUhdHftjg6WVX";
  +    sha256 = "638a7959d04e95f1e62abad02bd33702e4e8dfef98485ac7d9d50395c37e955d";
     };
   
     nativeBuildInputs = [
  
positive.code:     libxml2
      mutagen
      pythonPackages.pygobject
      python
      sg3-utils
      sqlite
      systemd_lib
  
negative.code:     zlib
    ];
  
    preConfigure = ''
      configureFlagsArray+=("--with-udev-dir=$out/share/udev")
    '';
  
    configureFlags = [
      "--disable-maintainer-mode"
      "--enable-nls"
      "--${boolEn (systemd_lib != null)}-udev"
      "--${boolEn (libxml2 != null)}-libxml"
      "--${boolEn (gdk-pixbuf != null)}-gdk-pixbuf"
      "--${boolEn (pythonPackages.pygobject != null)}-pygobject"
      "--disable-gtk-doc"
      "--disable-gtk-doc-html"
      "--disable-gtk-doc-pdf"
      "--disable-more-warnings"
      "--without-hal"
      "--${boolWt (libimobiledevice != null)}-libimobiledevice"
      "--${boolWt (pythonPackages.python != null)}-python"
      "--without-mono"
    ];
  
    postInstall =
      /* libgpod installs libgpod-sharp.pc unconditionally */ ''
        rm -vf $out/lib/pkgconfig/libgpod-sharp.pc
      '';
  
    passthru = {
      srcVerification = fetchurl rec {
        inherit (src)
          outputHash
          outputHashAlgo
          urls;
        failEarly = true;
        pgpsigUrls = map (n: "${n}.sign") src.urls;
        pgpKeyFingerprint = "A525 E3EA 186A AB45 DD0F  86AF 24A4 69FB 7A56 F78E";
      };
    };
  
    meta = with stdenv.lib; {
      description = "Library to access the contents of an iPod";
  