anchor.diff:        --replace "@PNMTOPS_NOSETPAGE@" "${netpbm}/bin/pnmtops -nosetpage"
     '';
   
  -  buildInputs = [ ghostscript psutils netpbm ];
  -  nativeBuildInputs = [ perl ];
  +  buildInputs = [ ghostscript psutils netpbm perl ];
   
     # Builds running without a chroot environment may detect the presence
     # of /usr/X11 in the host system, leading to an impure build of the
  
positive.code:     for f in 'man.local' 'mdoc.local'; do
          cat '${./site.tmac}' >>"$out/share/groff/site-tmac/$f"
      done
    '';
  
    meta = with stdenv.lib; {
  
negative.code:       version gxditview of the X11 xditview previewer, and an
        implementation of the -mm macros.
      '';
  
      outputsToInstall = [ "out" "perl" ];
    };
  }
  