python3Packages.chainer: mark cudaSupport broken

pkgs/development/python-modules/chainer/default.nix

@@ -1,6 +1,6 @@
-{ lib, buildPythonPackage, fetchFromGitHub, isPy3k
+{ config, lib, buildPythonPackage, fetchFromGitHub, isPy3k
 , filelock, protobuf, numpy, pytestCheckHook, mock, typing-extensions
-, cupy, cudaSupport ? false
+, cupy, cudaSupport ? config.cudaSupport or false
 }:
 
 buildPythonPackage rec {
@@ -39,6 +39,8 @@ buildPythonPackage rec {
   meta = with lib; {
     description = "A flexible framework of neural networks for deep learning";
     homepage = "https://chainer.org/";
+    # Un-break me when updating chainer next time!
+    broken = cudaSupport && (lib.versionAtLeast cupy.version "8.0.0");
     license = licenses.mit;
     maintainers = with maintainers; [ hyphon81 ];
   };