trying to add hpack to the build products

bashOutput

nix-build --show-trace -A all
error: while evaluating the attribute 'buildCommand' of the derivation 'reflex-project' at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/pkgs/stdenv/generic/make-derivation.nix:177:11:
while evaluating anonymous function at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/lib/attrsets.nix:225:10, called from undefined position:
while evaluating anonymous function at /nix/store/wsyx22606j37gin9nw4rn8zhn1gfdp6p-source/project/default.nix:198:36, called from /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/lib/attrsets.nix:225:16:
while evaluating 'optionalString' at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/lib/strings.nix:147:26, called from /nix/store/wsyx22606j37gin9nw4rn8zhn1gfdp6p-source/project/default.nix:198:44:
while evaluating 'concatMapStringsSep' at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/lib/strings.nix:64:33, called from /nix/store/wsyx22606j37gin9nw4rn8zhn1gfdp6p-source/project/default.nix:200:7:
while evaluating anonymous function at /nix/store/wsyx22606j37gin9nw4rn8zhn1gfdp6p-source/project/default.nix:200:33, called from undefined position:
while evaluating the attribute 'nativeBuildInputs' of the derivation 'backend-1.0.0.0' at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/pkgs/stdenv/generic/make-derivation.nix:177:11:
while evaluating the attribute 'nativeBuildInputs' of the derivation 'hpack-0.31.2' at /nix/store/pxh6ar7qdnx3w5vhpqpf0d9jr1bxrsy1-source/pkgs/stdenv/generic/make-derivation.nix:177:11:
infinite recursion encountered, at undefined position

default.nix

let reflex-platform = builtins.fetchGit {
      url = https://github.com/reflex-frp/reflex-platform.git;
      ref = "develop";
      rev = "f3ff81d519b226752c83eefd4df6718539c3efdc";
    };
in (import reflex-platform { }).project ({ pkgs, ... }: {
    packages = {
        common = ./common;
        backend = ./backend;
        frontend = ./frontend;
    };
    overrides = self: super: rec {
      hpack = self.callPackage ./packages/hpack.nix { };
      beam-core = self.callPackage ./packages/beam-core.nix { };
      beam-migrate = self.callPackage ./packages/beam-migrate.nix { };
      beam-postgres = self.callPackage ./packages/beam-postgres.nix { };
      servant-reflex = self.callPackage ./packages/servant-reflex.nix { };
      servant = pkgs.haskell.lib.dontCheck (pkgs.haskell.lib.overrideCabal super.servant (drv: {
        testHaskellDepends = []; # servant has a dependency on testdoc 0.16.0 which fails to build in nix
      }));
      backend = pkgs.haskell.lib.overrideCabal super.backend (drv: { enableSharedExecutables = false; });
      common = pkgs.haskell.lib.dontHaddock (pkgs.haskell.lib.overrideCabal super.common (drv: { libraryToolDepends = []; }));
      frontend = pkgs.haskell.lib.dontHaddock (pkgs.haskell.lib.overrideCabal super.frontend (drv: { libraryToolDepends = []; }));
    };

    shells = {
        ghc = ["common" "backend" "frontend"];
        ghcjs = ["common" "frontend"];
    };

    shellToolOverrides = ghc: super: {
        ccjs = pkgs.closurecompiler;
        vim = pkgs.vim;
    };
})