anchor.diff:    # Required binaries during execution
     # Python: Autocompletion generated from manpages and config editing
     propagatedBuildInputs = [ python which groff gettext ]
  -                          ++ stdenv.lib.optional (!stdenv.isDarwin) man_db
  +                          ++ stdenv.lib.optional (!stdenv.isDarwin) man-db
                             ++ [ bc coreutils ];
   
     postInstall = ''
  
positive.code: { stdenv, fetchurl, ncurses, nettools, python, which, groff, gettext, man_db,
    bc, libiconv, coreutils, gnused, kbd, utillinux, glibc }:
  
  stdenv.mkDerivation rec {
  
negative.code:     done
    '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
      sed -i "s|(hostname\||(${nettools}/bin/hostname\||" "$out/share/fish/functions/fish_prompt.fish"
      sed -i "s|Popen(\['manpath'|Popen(\['${man-db}/bin/manpath'|" "$out/share/fish/tools/create_manpage_completions.py"
      sed -i "s|command manpath|command ${man-db}/bin/manpath|" "$out/share/fish/functions/man.fish"
    '' + ''
      sed -i "s|/sbin /usr/sbin||" \
             "$out/share/fish/functions/__fish_complete_subcommand_root.fish"
  