anchor.diff:      atool
       autojump
       bazaar
  -    borgbackup
       curl
       cvs
       editorconfig-core-c
  -    gimp
       git
       git-lfs
       gitAndTools.hub
       gnupg
       gphoto2
  +    graphviz
       haskellPackages.pandoc
       haskellPackages.sizes
       htop
  
positive.code:     w3m
      wget
      ] ++ (if stdenv.isDarwin then [] else [
          calibre
          crawl
          darcs
  
negative.code:   fetchNixpkgs = import ./fetchNixpkgs.nix;
  
    nixpkgs = fetchNixpkgs {
       rev = "be5e8faafc69195ef47e9cf6b92806cf427656e1";
       sha256 = "0rvz7ac8bl2x9yrxrkzmgl3mwy4sjm0ngk44zfcfg81czgam7d6r";
    };
  
    pkgs = import nixpkgs { config = {}; };
  