anchor.diff:    ] ++ stdenv.lib.optionals enableGfanlib [
       cddlib
     ];
  -  nativeBuildInputs = [ autoconf bison perl pkgconfig autoreconfHook ];
  +  nativeBuildInputs = [
  +    bison
  +    perl
  +    pkgconfig
  +    autoreconfHook
  +  ];
   
  -  preConfigure = ''
  -    find . -type f -exec sed -e 's@/bin/rm@${coreutils}&@g' -i '{}' ';'
  -    find . -type f -exec sed -e 's@/bin/uname@${coreutils}&@g' -i '{}' ';'
  +  preAutoreconf = ''
  +    find . -type f -readable -writable -exec sed \
  +      -e 's@/bin/rm@${coreutils}&@g' \
  +      -e 's@/bin/uname@${coreutils}&@g' \
  +      -e 's@/usr/bin/file@${file}/bin/file@g' \
  +      -i '{}' ';'
     '';
   
     hardeningDisable = stdenv.lib.optional stdenv.isi686 "stackprotector";
  
positive.code: { stdenv, fetchurl, gmp, bison, perl, autoconf, ncurses, readline, coreutils, pkgconfig
  , autoreconfHook
  , flint
  , ntl
  , cddlib
  
negative.code:     sha256 = "0wvgz7l1b7zkpmim0r3mvv4fp8xnhlbz4c7hc90rn30snlansnf1";
    };
  
    configureFlags = [
      "--with-ntl=${ntl}"
    ] ++stdenv.lib.optionals enableFactory [
      "--enable-factory"
    ] ++ stdenv.lib.optionals enableGfanlib [
      "--enable-gfanlib"
  