anchor.diff: -{ config, lib, stdenv, fetchurl, fetchFromGitHub, pkgs, buildPackages
  +{ config, lib, stdenv, fetchurl, fetchpatch, fetchFromGitHub, pkgs, buildPackages
   , callPackage
   , enableThreading ? true, coreutils, makeWrapper
   }:
  
positive.code:       ]
        ++ optional stdenv.isSunOS ./ld-shared.patch
        ++ optionals stdenv.isDarwin [ ./cpp-precomp.patch ./sw_vers.patch ]
        ++ optional crossCompiling ./MakeMaker-cross.patch;
  
      # This is not done for native builds because pwd may need to come from
      # bootstrap tools when building bootstrap perl.
  
negative.code:       unset src
      '';
  
      # Build a thread-safe Perl with a dynamic libperl.so.  We need the
      # "installstyle" option to ensure that modules are put under
      # $out/lib/perl5 - this is the general default, but because $out
      # contains the string "perl", Configure would select $out/lib.
  