anchor.diff:    options_1_2 = dontCheck super.options_1_2;
     options = dontCheck super.options;
     statistics = dontCheck super.statistics;
  -  c2hs = if pkgs.stdenv.isDarwin then dontCheck super.c2hs else super.c2hs;
  +  c2hs = super.c2hs;
   
     # The package doesn't compile with ruby 1.9, which is our default at the moment.
     hruby = super.hruby.override { ruby = pkgs.ruby_2_1; };
  
positive.code: 
    # https://github.com/ndmitchell/shake/issues/206
    # https://github.com/ndmitchell/shake/issues/267
    shake = overrideCabal super.shake (drv: { doCheck = !pkgs.stdenv.isDarwin && false; });
  
    # https://github.com/nushio3/doctest-prop/issues/1
    doctest-prop = dontCheck super.doctest-prop;
  
negative.code:   # https://github.com/haskell/vector/issues/47
    vector = super.vector;
  
    halive = super.halive;
  
    # cabal2nix likes to generate dependencies on hinotify when hfsevents is really required
    # on darwin: https://github.com/NixOS/cabal2nix/issues/146.
    hinotify = super.hinotify;
  
    # hfsevents needs CoreServices in scope
    hfsevents = super.hfsevents;
  
    # FSEvents API is very buggy and tests are unreliable. See
    # http://openradar.appspot.com/10207999 and similar issues.
    # https://github.com/haskell-fswatch/hfsnotify/issues/62
    fsnotify = dontCheck super.fsnotify; # super.fsnotify;
  
    # the system-fileio tests use canonicalizePath, which fails in the sandbox
    system-fileio = super.system-fileio;
  
    # Prevents needing to add security_tool as a build tool to all of x509-system's
    # dependencies.
    x509-system = super.x509-system;
  
    double-conversion = super.double-conversion;
  
    # tests don't compile for some odd reason
    jwt = dontCheck super.jwt;
  