anchor.diff:                # Cf. https://gitlab.haskell.org/ghc/ghc/-/commit/ad2ef3a13f1eb000eab8e3d64592373b91a52806
                 ./haskell-overlays/splices-load-save/ghc-8.6-autoreconf.patch
               ];
  -          });
  +          })).override {
  +            bootPkgs = super.haskell.packages.ghc865Binary // {
  +              happy = super.haskell.packages.ghc865Binary.happy_1_19_12;
  +            };
  +          };
             ghcSplices-8_10 = (super.haskell.compiler.ghc8107.override {
               # New option for GHC 8.10. Explicitly enable profiling builds
               enableProfiledLibs = true;
  
positive.code:       haskellOverlays.combined
        (haskellOverlays.saveSplices "8.10")
        (self: super: with haskellLib; {
          blaze-textual = haskellLib.enableCabalFlag super.blaze-textual "integer-simple";
          cryptonite = disableCabalFlag super.cryptonite "integer-gmp";
          integer-logarithms = disableCabalFlag super.integer-logarithms "integer-gmp";
          scientific = enableCabalFlag super.scientific "integer-simple";
  
negative.code:               echo ${drv.version} >VERSION
                ./boot
              '' + drv.preConfigure or "";
            });
          };
          packages = super.haskell.packages // {
  