anchor.diff:      --enable-jit
       ${if unicodeSupport then "--enable-unicode-properties" else ""}
       ${if !cplusplusSupport then "--disable-cpp" else ""}
  -  '' + stdenv.lib.optionalString stdenv.isDarwin "CXXFLAGS=-O0";
  +  '' + optionalString stdenv.isDarwin "CXXFLAGS=-O0";
   
     doCheck = with stdenv; !(isCygwin || isFreeBSD);
       # XXX: test failure on Cygwin
       # we are running out of stack on both freeBSDs on Hydra
  +
  +  crossAttrs = optionalAttrs (stdenv.cross.config == "x86_64-w64-mingw32") {
  +    buildInputs = [ windows.mingw_w64_pthreads.crossDrv ];
  +  };
   
     meta = {
       homepage = "http://www.pcre.org/";
  
positive.code:       PCRE library is free, even for building proprietary software.
      '';
  
      platforms = stdenv.lib.platforms.all;
      maintainers = [ stdenv.lib.maintainers.simons ];
    };
  }
  
negative.code: { stdenv, fetchurl, unicodeSupport ? true, cplusplusSupport ? true
  , windows ? null
  }:
  
  with stdenv.lib;
  
  stdenv.mkDerivation rec {
    name = "pcre-8.34";
  