anchor.diff:  { lib, stdenv, fetchurl, pkgconfig, zlib, shadow
  -, ncurses ? null, perl ? null, pam, systemd, minimal ? false }:
  +, ncurses ? null, perl ? null, pam, systemd ? null, minimal ? false }:
   
   let
     version = lib.concatStringsSep "." ([ majorVersion ]
  
positive.code:       --replace "/bin/umount" "$out/bin/umount"
    '';
  
    crossAttrs = {
      # Work around use of `AC_RUN_IFELSE'.
      preConfigure = "export scanf_cv_type_modifier=ms" + lib.optionalString (systemd != null)
        "\nconfigureFlags+=\" --with-systemd --with-systemdsystemunitdir=$bin/lib/systemd/system/\"";
    };
  
    preConfigure = lib.optionalString (systemd != null) ''
      configureFlags+=" --with-systemd --with-systemdsystemunitdir=$bin/lib/systemd/system/"
    '';
  
negative.code:     "--disable-use-tty-group"
      "--enable-fs-paths-default=/run/wrappers/bin:/var/run/current-system/sw/bin:/sbin"
      "--disable-makeinstall-setuid" "--disable-makeinstall-chown"
    ] ++ lib.optional (ncurses == null) "--without-ncurses"
      ++ lib.optional (stdenv.hostPlatform != stdenv.buildPlatform)
         "scanf_cv_type_modifier=ms"
    ;
  
    makeFlags = "usrbin_execdir=$(bin)/bin usrsbin_execdir=$(bin)/sbin";
  
  