anchor.diff: -{ lib, stdenv, buildPackages, fetchurl, pkg-config, pcre, libxml2, zlib, bzip2, which, file
  +{ lib, stdenv, buildPackages, fetchurl, pkg-config, pcre2, libxml2, zlib, bzip2, which, file
   , openssl
   , enableDbi ? false, libdbi
   , enableMagnet ? false, lua5_1
  
positive.code:                 ++ lib.optional enableExtendedAttrs "--with-attr";
  
    preConfigure = ''
      export PATH=$PATH:${pcre.dev}/bin
      sed -i "s:/usr/bin/file:${file}/bin/file:g" configure
    '';
  
  
negative.code:   depsBuildBuild = [ buildPackages.stdenv.cc ];
  
    nativeBuildInputs = [ pkg-config ];
    buildInputs = [ pcre2 pcre2.dev libxml2 zlib bzip2 which file openssl ]
               ++ lib.optional enableDbi libdbi
               ++ lib.optional enableMagnet lua5_1
               ++ lib.optional enableMysql libmysqlclient
  