anchor.diff:  
     # Use the default version of mysql to build this package (which is actually mariadb).
     mysql = super.mysql.override { mysql = pkgs.mysql.lib; };
  -
  -  # Please also remove optparse-applicative special case from
  -  # cabal2nix/hackage2nix.hs when removing the following.
  -  elm-make = super.elm-make.override { optparse-applicative = self.optparse-applicative_0_10_0; };
  -  elm-package = super.elm-package.override { optparse-applicative = self.optparse-applicative_0_10_0; };
   
     # Link the proper version.
     zeromq4-haskell = super.zeromq4-haskell.override { zeromq = pkgs.zeromq4; };
  
positive.code:   dotfs = dontCheck super.dotfs;                        # http://hydra.cryp.to/build/498599/log/raw
    DRBG = dontCheck super.DRBG;                          # http://hydra.cryp.to/build/498245/nixlog/1/raw
    either-unwrap = dontCheck super.either-unwrap;        # http://hydra.cryp.to/build/498782/log/raw
    elm-repl = dontCheck super.elm-repl;                  # http://hydra.cryp.to/build/501878/nixlog/1/raw
    etcd = dontCheck super.etcd;
    fb = dontCheck super.fb;                              # needs credentials for Facebook
    fptest = dontCheck super.fptest;                      # http://hydra.cryp.to/build/499124/log/raw
  
negative.code:   # https://github.com/aka-bash0r/multi-cabal/issues/4
    multi-cabal = markBroken super.multi-cabal;
  
    # Elm is no longer actively maintained on Hackage: https://github.com/NixOS/nixpkgs/pull/9233.
    Elm = markBroken super.Elm;
    elm-bridge = markBroken super.elm-bridge;
    elm-build-lib = markBroken super.elm-build-lib;
    elm-compiler = markBroken super.elm-compiler;
    elm-core-sources = markBroken super.elm-core-sources;
    elm-get = markBroken super.elm-get;
    elm-init = markBroken super.elm-init;
    elm-make = markBroken super.elm-make;
    elm-package = markBroken super.elm-package;
    elm-reactor = markBroken super.elm-reactor;
    elm-repl = markBroken super.elm-repl;
    elm-server = markBroken super.elm-server;
    elm-yesod = markBroken super.elm-yesod;
  
  }
  