anchor.diff:  
     raul = callPackage ../development/libraries/audio/raul { };
   
  -  readline = readline6; # 6.2 works, 6.3 breaks python, parted
  +  readline = readline6;
  +  readline6 = readline63;
   
     readline4 = callPackage ../development/libraries/readline/readline4.nix { };
   
     readline5 = callPackage ../development/libraries/readline/readline5.nix { };
   
  -  readline6 = callPackage ../development/libraries/readline/readline6.nix { };
  +  readline62 = callPackage ../development/libraries/readline/readline6.nix { };
   
     readline63 = callPackage ../development/libraries/readline/readline6.3.nix { };
   
  
positive.code:     suitesparse = null;
      openjdk = null;
      gnuplot = null;
      readline = readline63;
    };
    octaveFull = (lowPrio (callPackage ../development/interpreters/octave {
      fltk = fltk13;
  
negative.code: 
    gdb = callPackage ../development/tools/misc/gdb {
      hurd = gnu.hurdCross;
      inherit (gnu) mig;
    };
  
  