anchor.diff:        } // stdenv.lib.optionalAttrs (!noGcTest) {
           # The headless browser run as part of gc tests would hang/crash without this
           preCheck = ''
  -          export FONTCONFIG_PATH=${fontconfig.out}/etc/fonts
  +          export FONTCONFIG_PATH=${pkgs.fontconfig.out}/etc/fonts
           '';
  -      }))
  -    {};
  -  reflex-dom = haskellPackages.callPackage
  -    ({ android-activity }: haskellLib.overrideCabal
  +      });
  +  reflex-dom = haskellLib.overrideCabal
         (haskellPackages.callCabal2nix "reflex-dom" ./reflex-dom { })
         (drv: {
           # Hack until https://github.com/NixOS/cabal2nix/pull/432 lands
           libraryHaskellDepends = (drv.libraryHaskellDepends or []) ++ stdenv.lib.optionals (with stdenv.hostPlatform; isAndroid && is32bit) [
  -          android-activity
  +          haskellPackages.android-activity
           ];
  -      }))
  -    {};
  +      });
     chrome-test-utils = haskellPackages.callCabal2nix "chrome-test-utils" ./chrome-test-utils {};
   }
  
positive.code:   inherit (pkgs) stdenv;
    haskellLib = pkgs.haskell.lib;
  in {
    reflex-dom-core = haskellPackages.callPackage
      ({ temporary, jsaddle-warp, process, chrome-test-utils
       , selenium-server-standalone, which, fontconfig, chromium, pkgs
       }: let
        inherit (haskellPackages) ghc;
        noGcTest = stdenv.hostPlatform.system != "x86_64-linux"
                || stdenv.hostPlatform != stdenv.buildPlatform
  
negative.code:         # Show some output while running tests, so we might notice what's wrong
          testTarget = "--show-details=streaming";
  
          testHaskellDepends = with haskellPackages; (drv.testHaskellDepends or []) ++ stdenv.lib.optionals (!noGcTest) [
            temporary
            jsaddle-warp
            process
            chrome-test-utils
          ];
  
          testSystemDepends = with pkgs; (drv.testSystemDepends or []) ++ [
            selenium-server-standalone which
          ] ++ stdenv.lib.optionals (!noGcTest) [
            chromium
  