anchor.diff:  
     # Tries to mess with extended POSIX attributes, but can't in our chroot environment.
     xattr = dontCheck super.xattr;
  +
  +  # Disable test suites to fix the build.
  +  acme-year = dontCheck super.acme-year;                # http://hydra.cryp.to/build/497858/log/raw
  +  aeson-lens = dontCheck super.aeson-lens;              # http://hydra.cryp.to/build/496769/log/raw
  +  apache-md5 = dontCheck super.apache-md5;              # http://hydra.cryp.to/build/498709/nixlog/1/raw
  +  app-settings = dontCheck super.app-settings;          # http://hydra.cryp.to/build/497327/log/raw
  +  binary-protocol = dontCheck super.binary-protocol;    # http://hydra.cryp.to/build/499749/log/raw
  +  bindings-GLFW = dontCheck super.bindings-GLFW;        # http://hydra.cryp.to/build/497379/log/raw
  +  bits = dontCheck super.bits;                          # http://hydra.cryp.to/build/500239/log/raw
  +  bloodhound = dontCheck super.bloodhound;
  +  burst-detection = dontCheck super.burst-detection;    # http://hydra.cryp.to/build/496948/log/raw
  +  cabal-bounds = dontCheck super.cabal-bounds;          # http://hydra.cryp.to/build/496935/nixlog/1/raw
  +  cabal-meta = dontCheck super.cabal-meta;              # http://hydra.cryp.to/build/497892/log/raw
  +  cautious-file = dontCheck super.cautious-file;        # http://hydra.cryp.to/build/499730/log/raw
  +  cjk = dontCheck super.cjk;
  +  command-qq = dontCheck super.command-qq;              # http://hydra.cryp.to/build/499042/log/raw
  +  craftwerk = dontCheck super.craftwerk;
  +  crypto-pubkey = dontCheck super.crypto-pubkey;
  +  damnpacket = dontCheck super.damnpacket;              # http://hydra.cryp.to/build/496923/log
  +  Deadpan-DDP = dontCheck super.Deadpan-DDP;            # http://hydra.cryp.to/build/496418/log/raw
  +  directory-layout = dontCheck super.directory-layout;
  +  docopt = dontCheck super.docopt;                      # http://hydra.cryp.to/build/499172/log/raw
  +  dom-selector = dontCheck super.dom-selector;          # http://hydra.cryp.to/build/497670/log/raw
  +  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
  +  fptest = dontCheck super.fptest;                      # http://hydra.cryp.to/build/499124/log/raw
  +  ghc-events = dontCheck super.ghc-events;              # http://hydra.cryp.to/build/498226/log/raw
  +  ghc-events-parallel = dontCheck super.ghc-events-parallel;    # http://hydra.cryp.to/build/496828/log/raw
  +  ghcid = dontCheck super.ghcid;
  +  ghc-imported-from = dontCheck super.ghc-imported-from;
  +  ghc-mod = dontCheck super.ghc-mod;                    # http://hydra.cryp.to/build/499674/log/raw
  +  ghc-parmake = dontCheck super.ghc-parmake;
  +  gitlib-cmdline = dontCheck super.gitlib-cmdline;
  +  git-vogue = dontCheck super.git-vogue;
  +  GLFW-b = dontCheck super.GLFW-b;
  +  hackport = dontCheck super.hackport;
  +  hadoop-formats = dontCheck super.hadoop-formats;
  +  haeredes = dontCheck super.haeredes;
  +  hashed-storage = dontCheck super.hashed-storage;
  +  hashring = dontCheck super.hashring;
  +  hath = dontCheck super.hath;
  +  hdbi-postgresql = dontCheck super.hdbi-postgresql;
  +  hedis = dontCheck super.hedis;
  +  hedis-pile = dontCheck super.hedis-pile;
  +  hedis-tags = dontCheck super.hedis-tags;
  +  hedn = dontCheck super.hedn;
  +  hgdbmi = dontCheck super.hgdbmi;
  +  hi = dontCheck super.hi;
  +  hmatrix-tests = dontCheck super.hmatrix-tests;
  +  hPDB-examples = dontCheck super.hPDB-examples;
  +  hquery = dontCheck super.hquery;
  +  hs2048 = dontCheck super.hs2048;
  +  hsbencher = dontCheck super.hsbencher;
  +  hsexif = dontCheck super.hsexif;
  +  hspec-server = dontCheck super.hspec-server;
  +  HTF = dontCheck super.HTF;
  +  htsn = dontCheck super.htsn;
  +  htsn-import = dontCheck super.htsn-import;
  +  http2 = dontCheck super.http2;
  +  http-client-openssl = dontCheck super.http-client-openssl;
  +  ihaskell = dontCheck super.ihaskell;
  +  influxdb = dontCheck super.influxdb;
  +  itanium-abi = dontCheck super.itanium-abi;
  +  language-slice = dontCheck super.language-slice;
  +  lensref = dontCheck super.lensref;
  +  liquidhaskell = dontCheck super.liquidhaskell;
  +  lvmrun = dontCheck super.lvmrun;
  +  memcache = dontCheck super.memcache;
  +  milena = dontCheck super.milena;
  +  nats-queue = dontCheck super.nats-queue;
  +  netpbm = dontCheck super.netpbm;
  +  network-dbus = dontCheck super.network-dbus;
  +  notcpp = dontCheck super.notcpp;
  +  ntp-control = dontCheck super.ntp-control;
  +  numerals = dontCheck super.numerals;
  +  opaleye = dontCheck super.opaleye;
  +  openpgp = dontCheck super.openpgp;
  +  optional = dontCheck super.optional;
  +  os-release = dontCheck super.os-release;
  +  persistent-redis = dontCheck super.persistent-redis;
  +  pipes-extra = dontCheck super.pipes-extra;
  +  pipes-websockets = dontCheck super.pipes-websockets;
  +  postgresql-simple-migration = dontCheck super.postgresql-simple-migration;
  +  process-streaming = dontCheck super.process-streaming;
  +  punycode = dontCheck super.punycode;
  +  pwstore-cli = dontCheck super.pwstore-cli;
  +  quantities = dontCheck super.quantities;
  +  redis-io = dontCheck super.redis-io;
  +  rethinkdb = dontCheck super.rethinkdb;
  +  Rlang-QQ = dontCheck super.Rlang-QQ;
  +  sai-shape-syb = dontCheck super.sai-shape-syb;
  +  scp-streams = dontCheck super.scp-streams;
  +  separated = dontCheck super.separated;
  +  shadowsocks = dontCheck super.shadowsocks;
  +  shake-language-c = dontCheck super.shake-language-c;
  +  static-resources = dontCheck super.static-resources;
  +  svndump = dontCheck super.svndump;
  +  thumbnail-plus = dontCheck super.thumbnail-plus;
  +  tickle = dontCheck super.tickle;
  +  tpdb = dontCheck super.tpdb;
  +  translatable-intset = dontCheck super.translatable-intset;
  +  ua-parser = dontCheck super.ua-parser;
  +  unagi-chan = dontCheck super.unagi-chan;
  +  wai-logger = dontCheck super.wai-logger;
  +  WebBits = dontCheck super.WebBits;                    # http://hydra.cryp.to/build/499604/log/raw
  +  webdriver = dontCheck super.webdriver;
  +  xcffib = dontCheck super.xcffib;
  +  xsd = dontCheck super.xsd;
  +
  +  # https://github.com/athanclark/dag/issues/2
  +  dag = addBuildTool super.dag self.Cabal_1_22_0_0;     # http://hydra.cryp.to/build/498554/log/raw
   
   }
   // {
  
positive.code: 
    # jailbreak doesn't get the job done because the Cabal file uses conditionals a lot.
    darcs = overrideCabal super.darcs (drv: {
      patchPhase = "sed -i -e 's|random.*==.*|random|' -e 's|text.*>=.*,|text,|' -e s'|terminfo == .*|terminfo|' darcs.cabal";
    });
  
  
negative.code:   tasty-kat = dontCheck super.tasty-kat;
  
    # These packages try to execute non-existent external programs.
    cmaes = dontCheck super.cmaes;                        # http://hydra.cryp.to/build/498725/log/raw
    filestore = dontCheck super.filestore;
    Hclip = dontCheck super.Hclip;
    HList = dontCheck super.HList;
    memcached-binary = dontCheck super.memcached-binary;
    postgresql-simple = dontCheck super.postgresql-simple;
    snowball = dontCheck super.snowball;
    xmlgen = dontCheck super.xmlgen;
  
    # These packages try to access the network.
    concurrent-dns-cache = dontCheck super.concurrent-dns-cache;
    dbus = dontCheck super.dbus;                          # http://hydra.cryp.to/build/498404/log/raw
    http-client = dontCheck super.http-client;            # http://hydra.cryp.to/build/501430/nixlog/1/raw
    js-jquery = dontCheck super.js-jquery;
    riak = dontCheck super.riak;                          # http://hydra.cryp.to/build/498763/log/raw
    warp = dontCheck super.warp;                          # http://hydra.cryp.to/build/501073/nixlog/5/raw
  
    # https://github.com/NICTA/digit/issues/3
    digit = dontCheck super.digit;
  