anchor.diff:  , fetchurl
   , flex
   , gettext
  +, lib
   , libtool
   
   , libexif
  
positive.code: }:
  
  let
    inherit (stdenv.lib)
      wtFlag;
  in
  
  stdenv.mkDerivation rec {
    name = "libgphoto2-2.5.10";
  
    src = fetchurl {
      url = "mirror://sourceforge/gphoto/${name}.tar.bz2";
      sha256 = "8d8668d432ba595c7466442aec2cf553bdf8782ec171291dbc65717c633a4ef2";
    };
  
    nativeBuildInputs = [
  
negative.code:     "--enable-largefile"
      "--disable-internal-docs"
      "--disable-docs"
      "--${boolWt (libjpeg-turbo_1-4 != null)}-jpeg"
      "--with-camlibs=all"
    ];
  
    passthru = {
      srcVerification = fetchurl rec {
        inherit (src)
          outputHash
          outputHashAlgo
          urls;
        pgpsigUrls = map (n: "${n}.asc") src.urls;
        # Marcus Meissner
        pgpKeyFingerprint = "7C4A FD61 D8AA E757 0796  A517 2209 D690 2F96 9C95";
        failEarly = true;
      };
    };
  
    meta = with lib; {
      description = "A library for accessing digital cameras";
      homepage = http://www.gphoto.org/proj/libgphoto2/;
      license = licenses.gpl2;
  