anchor.diff:    preConfigure = ''
       export ac_cv_func_setpgrp_void=yes
       export shadow_cv_logdir=/var/log
  +    (
  +    head -n -1 "${docbook_xml_dtd_412}/xml/dtd/docbook/catalog.xml" 
  +    tail -n +3 "${docbook_xsl}/share/xml/docbook-xsl/catalog.xml"
  +    ) > xmlcatalog
  +    configureFlags="$configureFlags --with-xml-catalog=$PWD/xmlcatalog ";
     '';
  +
  +  configureFlags = " --enable-man ";
   
     preBuild = assert glibc != null;
       ''
  
positive.code: in
  
  stdenv.mkDerivation rec {
    name = "shadow-4.2.1";
  
    src = fetchurl {
      url = "http://pkg-shadow.alioth.debian.org/releases/${name}.tar.xz";
      sha256 = "0h9x1zdbq0pqmygmc1x459jraiqw4gqz8849v268crk78z8r621v";
    };
  
    buildInputs = stdenv.lib.optional (pam != null && stdenv.isLinux) pam;
  
    patches = [ ./keep-path.patch dots_in_usernames ];
  
  
negative.code: { stdenv, fetchurl, fetchFromGitHub, autoreconfHook, libxslt, libxml2
  , docbook_xml_dtd_412, docbook_xsl, gnome_doc_utils, flex, bison
  , pam ? null, glibcCross ? null }:
  
  let
  
  