anchor.diff:  
     buildPhase = ''
       scons PREFIX="$out" OPENSSL="${openssl}" ZLIB="${zlib}" APR="$(echo "${apr.dev}"/bin/*-config)" CFLAGS="-I${zlib.dev}/include" \
  -      LINKFLAGS="-L${zlib.out}/lib -L${expat}/lib -L${openldap}/lib" \
  +      LINKFLAGS="-L${zlib.out}/lib -L${expat}/lib -L${openldap}/lib -L${libiconv}/lib" \
           APU="$(echo "${aprutil.dev}"/bin/*-config)" CC="${
             if stdenv.cc.isClang then "clang" else "${stdenv.cc}/bin/gcc"
           }" ${
  
positive.code:   };
  
    nativeBuildInputs = [ pkgconfig ];
    buildInputs = [ apr scons openssl aprutil zlib ]
      ++ stdenv.lib.optional (!stdenv.isCygwin) kerberos;
  
    postPatch = ''
  
negative.code: { stdenv, fetchurl, apr, scons, openssl, aprutil, zlib, kerberos
  , pkgconfig, gnused, expat, openldap, libiconv }:
  
  stdenv.mkDerivation rec {
    name = "serf-1.3.9";
  