{ sources ? import ../nix/sources.nix
, ...
}:
(self: super:
  let pkgs = self; in
  {
    haskell = super.haskell // {
      packageOverrides = pkgs.lib.composeManyExtensions [
        super.haskell.packageOverrides
        (self: super: {
          achat = (self.callCabal2nix "achat" ../. { }).overrideAttrs (_: {
            postInstall = ''
              mkdir -p $out/share
              cp -a ./dist/build/achat/achat.jsexe $out/share
            '';
          });
          haskell-halogen-core = pkgs.haskell.lib.dontCheck (self.callCabal2nix "haskell-halogen-core" sources.haskell-halogen { });
          protolude = pkgs.haskell.lib.dontHaddock (
            pkgs.haskell.lib.appendConfigureFlags (pkgs.haskell.lib.doJailbreak super.protolude) [
              "--ghc-option=-fno-safe-haskell"
              "--ghc-option=-fno-warn-x-partial"
            ]);
          clay = self.callHackage "clay" "0.15.0" { };
        })
      ];
    };
  })