anchor.diff:    apiary-session = dontCheck super.apiary-session;
     apiary-websockets = dontCheck super.apiary-websockets;
   
  -  # https://github.com/mikeizbicki/hmm/issues/12
  -  hmm = markBroken super.hmm;
  -
     # https://github.com/alephcloud/hs-configuration-tools/issues/40
     configuration-tools = dontCheck super.configuration-tools;
   
  -  # https://github.com/fumieval/karakuri/issues/1
  -  karakuri = markBroken super.karakuri;
  -
  -  # Upstream notified by e-mail.
  -  gearbox = markBroken super.gearbox;
  -
  -  # https://github.com/deech/fltkhs/issues/7
  -  fltkhs = markBroken super.fltkhs;
  -
  -  # Build fails, but there seems to be no issue tracker available. :-(
  -  hmidi = markBrokenVersion "0.2.1.0" super.hmidi;
  -  padKONTROL = markBroken super.padKONTROL;
  -  Bang = dontDistribute super.Bang;
  -  launchpad-control = dontDistribute super.launchpad-control;
  -
  -  # Upstream provides no issue tracker and no contact details.
  -  vivid = markBroken super.vivid;
  -
     # Test suite wants to connect to $DISPLAY.
     hsqml = dontCheck (super.hsqml.override { qt5 = pkgs.qt53; });
   
  -  # https://github.com/lookunder/RedmineHs/issues/4
  -  Redmine = markBroken super.Redmine;
  -
     # HsColour: Language/Unlambda.hs: hGetContents: invalid argument (invalid byte sequence)
     unlambda = dontHyperlinkSource super.unlambda;
  -
  -  # https://github.com/megantti/rtorrent-rpc/issues/2
  -  rtorrent-rpc = markBroken super.rtorrent-rpc;
   
     # https://github.com/PaulJohnson/geodetics/issues/1
     geodetics = dontCheck super.geodetics;
  
positive.code:           substituteInPlace double-conversion.cabal --replace stdc++ c++
          '';
        });
  
    # Obsolete: https://github.com/massysett/prednote/issues/1.
    prednote-test = markBrokenVersion "0.26.0.4" super.prednote-test;
  
    # Obsolete.
    lushtags = markBrokenVersion "0.0.1" super.lushtags;
  
    # tests don't compile for some odd reason
    jwt = dontCheck super.jwt;
  
negative.code:   # https://github.com/commercialhaskell/stack/issues/409
    stack = overrideCabal super.stack (drv: { preCheck = "export HOME=$TMPDIR"; doCheck = false; });
  
    # Hydra no longer allows building texlive packages.
    lhs2tex = dontDistribute super.lhs2tex;
  
  