anchor.diff:  
     # Some packages need a non-core version of Cabal.
     Cabal_1_18_1_6 = dontCheck super.Cabal_1_18_1_6;
  -  Cabal_1_20_0_3 = doJailbreak (dontCheck super.Cabal_1_20_0_3);
  +  Cabal_1_20_0_3 = dontCheck super.Cabal_1_20_0_3;
     Cabal_1_22_0_0 = dontCheck super.Cabal_1_22_0_0;
     cabal-install = dontCheck (super.cabal-install.override { Cabal = self.Cabal_1_22_0_0; });
   
  
positive.code:   # https://github.com/techtangents/ablist/issues/1
    ABList = dontCheck super.ABList;
  
    # https://github.com/gcross/AbortT-transformers/issues/1
    AbortT-transformers = doJailbreak super.AbortT-transformers;
  
    # Depends on broken NewBinary package.
    ASN1 = markBroken super.ASN1;
  
  
negative.code:   hbro-contrib = markBroken super.hbro-contrib;
  
    # https://github.com/prowdsponsor/fb/pull/33
    fb = overrideCabal super.fb (drv: {
      patches = [
        (pkgs.fetchpatch {
          url = https://github.com/prowdsponsor/fb/pull/31.patch;
          sha256 = "0ip8mhpbbvlp4pz7d27d6cg39gm6ypfsf4rdmfrmdh3pkig0axls";
        })
      ];
    });
  
    # https://github.com/haskell/vector/issues/47
    vector = if pkgs.stdenv.isi686 then appendConfigureFlag super.vector "--ghc-options=-msse2" else super.vector;
  