anchor.diff:        hspec
   
         # useful libraries...
  +      MonadCatchIO-transformers
         Unixutils
         array
         blaze-html
         bytestring
         containers
         extra
  +      heist
         hsexif
  +      hspec
  +      hspec-core
  +      hspec-snap
         lens
         mtl
  +      mtl
         optparse-applicative
  +      postgresql-simple
         process
         regex-applicative
         regex-base
  
positive.code: {
    allowUnfree = true;
  
    # define a environment i can install/update with
    #
    # $ nix-env -iA nixpkgs.all
    packageOverrides = super: let self = super.pkgs; in with self; rec {
  
      all = buildEnv {
        name = "all";
        paths = [
          phocid
          pinfold
          ybapp
  
          myHaskellEnv
          cabal2nix
  
negative.code:       regex-tdfa
        shakespeare
        snap
        snap-core
        snap-loader-dynamic
        snap-loader-static
        snap-server
        snaplet-postgresql-simple
        snaplet-sass
        text
        time
        transformers
        vector
        xlsx
      ]);
  