{ pngSupport ? true , stdenv, fetchurl, x11, libpng ? null}: assert x11 != null; assert pngSupport -> libpng != null; stdenv.mkDerivation { name = "zvbi-0.2.16"; src = fetchurl { url = http://nix.cs.uu.nl/dist/tarballs/zvbi-0.2.16.tar.bz2; md5 = "6ed822ae5d0766129bfa1508394b6ac0"; }; buildInputs = [x11 (if pngSupport then libpng else null)]; inherit pngSupport; }