anchor.diff:    outputs = [ "out" "doc" ];
     outputMan = "out"; # users will want `man man` to work
   
  -  nativeBuildInputs = [ pkgconfig ];
  +  nativeBuildInputs = [ pkgconfig makeWrapper ];
     buildInputs = [ libpipeline db groff ];
  -  troff="${groff}/bin/groff";
   
     postPatch = ''
       substituteInPlace src/man_db.conf.in \
  
positive.code:     # Don't try /etc/man_db.conf by default, so we avoid error messages.
      "--with-config-file=\${out}/etc/man_db.conf"
      "--with-systemdtmpfilesdir=\${out}/lib/tmpfiles.d"
      "--with-eqn=${groff}/bin/eqn"
      "--with-neqn=${groff}/bin/neqn"
      "--with-nroff=${groff}/bin/nroff"
      "--with-pic=${groff}/bin/pic"
      "--with-refer=${groff}/bin/refer"
      "--with-tbl=${groff}/bin/tbl"
    ];
  
    enableParallelBuilding = true;
  
  
negative.code: { stdenv, fetchurl, pkgconfig, libpipeline, db, groff, makeWrapper }:
  
  stdenv.mkDerivation rec {
    name = "man-db-2.7.5";
  