anchor.diff: -{ stdenv, fetchurl, perl, nettools, java, polyml, z3 }:
  +{ stdenv, fetchurl, perl, nettools, java, polyml, z3, rlwrap }:
   # nettools needed for hostname
   
   stdenv.mkDerivation rec {
  
positive.code:       ML_SOURCES="\$POLYML_HOME/src"
      EOF
  
      for comp in contrib/jdk contrib/polyml-*; do
        rm -rf $comp/x86*
      done
      '' + (if ! stdenv.isLinux then "" else ''
  
negative.code:   sourceRoot = dirname;
  
    postPatch = ''
      patchShebangs .
  
      cat >contrib/z3*/etc/settings <<EOF
        Z3_HOME=${z3}
        Z3_VERSION=${z3.version}
        Z3_SOLVER=${z3}/bin/z3
        Z3_INSTALLED=yes
      EOF
  
      cat >contrib/polyml-*/etc/settings <<EOF
        ML_SYSTEM_64=true
  