anchor.diff:  
           };
   
  -        lowdown-nix = with final; stdenv.mkDerivation rec {
  +        lowdown-nix = with final; currentStdenv.mkDerivation rec {
             name = "lowdown-0.9.0";
   
             src = lowdown-src;
  
positive.code:               mkdir -p $out/lib
                cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
                rm -f $out/lib/*.a
                ${lib.optionalString stdenv.isLinux ''
                  chmod u+w $out/lib/*.so.*
                  patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
                ''}
              '';
  
  
negative.code:                 pkgs.perl
                  boost
                ]
                ++ lib.optional (currentStdenv.isLinux || currentStdenv.isDarwin) libsodium
                ++ lib.optional currentStdenv.isDarwin darwin.apple_sdk.frameworks.Security;
  
              configureFlags = ''
                --with-dbi=${perlPackages.DBI}/${pkgs.perl.libPrefix}
  