anchor.diff:        inherit sha256;
       };
   
  -    outputs = [ "out" "man" ];
  +    # TODO: Add a "dev" output containing the header files.
  +    outputs = [ "out" "man" "docdev" ];
  +    setOutputFlags = false;
   
       patches =
         [ # Do not look in /usr etc. for dependencies.
  
positive.code: let
  
    libc = if stdenv.cc.libc or null != null then stdenv.cc.libc else "/usr";
  
    common = { version, sha256 }: stdenv.mkDerivation rec {
      name = "perl-${version}";
  
  
negative.code:       ++ optional stdenv.isSunOS ./ld-shared.patch
        ++ optional stdenv.isDarwin [ ./cpp-precomp.patch ];
  
      postPatch = ''
        pwd="$(type -P pwd)"
        substituteInPlace dist/PathTools/Cwd.pm \
          --replace "/bin/pwd" "$pwd"
      '';
      sandboxProfile = sandbox.allow "ipc-sysv-sem";
  
      # Build a thread-safe Perl with a dynamic libperls.o.  We need the
  