final: prev:
{
  haskell-nix = prev.haskell-nix // ({
    defaultModules = prev.haskell-nix.defaultModules ++ final.lib.optional final.stdenv.hostPlatform.isGhcjs (
      ({ pkgs, buildModules, config, lib, ... }: {
        # Allow Cabal to be reinstalled so that custom setups will use a Cabal
        # built with packages.Cabal.patches
        nonReinstallablePkgs =
          [ "rts" "ghc-heap" "ghc-prim" "integer-gmp" "integer-simple" "base"
            "deepseq" "array" "ghc-boot-th" "pretty" "template-haskell"
            "ghcjs-prim" "ghcjs-th"
          ]
          ++ lib.optionals (!config.reinstallableLibGhc) [
            "ghc-boot"
            "ghc" "Win32" "array" "binary" "bytestring" "containers"
            "directory" "filepath" "ghc-boot" "ghc-compact" "ghc-prim"
            "hpc"
            "mtl" "parsec" "process" "text" "time" "transformers"
            "unix" "xhtml" "terminfo"
          ];
        # Include patches for custom setups
        packages.Cabal.patches = [
          ./patches/Cabal/Cabal-3.0.0.0-drop-pkg-db-check.diff
          ./patches/Cabal/Cabal-3.0.0.0-no-final-checks.diff
        ];
        testWrapper = [((final.writeScriptBin "node-wrapper" ''
          set -euo pipefail
          exe=$1
          shift
          ${final.buildPackages.nodejs}/bin/node $exe $@
        '') + "/bin/node-wrapper")];
      })
    );
  });
}