anchor.diff: -{ stdenv, fetchurl, fetchpatch, replace, curl, expat, zlib, bzip2, libarchive
  +{ stdenv, fetchurl, fetchpatch, replace, curl, expat, zlib, bzip2
   , useNcurses ? false, ncurses, useQt4 ? false, qt4, wantPS ? false, ps ? null
   }:
   
  
positive.code:     (concatMap (p: [ (p.dev or p) (p.out or p) ]) buildInputs);
  
    configureFlags =
      "--docdir=/share/doc/${name} --mandir=/share/man --system-libs"
      + stdenv.lib.optionalString useQt4 " --qt-gui";
  
    setupHook = ./setup-hook.sh;
  
negative.code:       sha256 = "16acmdr27adma7gs9rs0dxdiqppm15vl3vv3agy7y8s94wyh4ybv";
      });
  
    buildInputs = [ curl expat zlib bzip2 ]
      ++ optional useNcurses ncurses
      ++ optional useQt4 qt4;
  
  