anchor.diff:  #
   #  mp4v2 = callPackage ../development/libraries/mp4v2 { };
   #
  -#  libmpc = callPackage ../development/libraries/libmpc { };
  +  libmpc = callPackage ../development/libraries/libmpc { };
   #
   #  mpich2 = callPackage ../development/libraries/mpich2 { };
   #
  
positive.code: #
  #  cron = callPackage ../tools/system/cron { };
  #
  #  cudatoolkit5 = callPackage ../development/compilers/cudatoolkit/5.5.nix { };
  #
  #  cudatoolkit6 = callPackage ../development/compilers/cudatoolkit/6.0.nix { };
  #
  #  cudatoolkit65 = callPackage ../development/compilers/cudatoolkit/6.5.nix { };
  #
  #  cudatoolkit7 = callPackage ../development/compilers/cudatoolkit/7.0.nix { };
  #
  #  cudatoolkit = cudatoolkit7;
  #
  #  curl = curlFull.override {
  #    suffix = "";
  #  };
  #
  #  curlFull = callPackage ../tools/networking/curl { suffix = "full"; };
  #
  #  curl3 = callPackage ../tools/networking/curl/7.15.nix rec {
  #    zlibSupport = true;
  #    sslSupport = zlibSupport;
  #  };
  #
  #  curl_unix_socket = callPackage ../tools/networking/curl-unix-socket rec { };
  #
  #  cunit = callPackage ../tools/misc/cunit { };
  #
  #  curlftpfs = callPackage ../tools/filesystems/curlftpfs { };
  
negative.code: #
  #  libvterm = callPackage ../development/libraries/libvterm { };
  #
    libvorbis = callPackage ../development/libraries/libvorbis { };
  
    libwebp = callPackage ../development/libraries/libwebp { };
  #
  #  libwmf = callPackage ../development/libraries/libwmf { };
  #
  