From ecc51e4b3368dc031846199f38756c0f0082297e Mon Sep 17 00:00:00 2001
From: LiuYuHui <liuyuhui002@foxmail.com>
Date: Wed, 5 Aug 2020 21:40:48 +0800
Subject: [PATCH] make CI happy

---
 mypy/checker.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mypy/checker.py b/mypy/checker.py
index b8976dbcb54e9..26d41f558fa54 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -947,7 +947,8 @@ def check_func_def(self, defn: FuncItem, typ: CallableType, name: Optional[str])
                             if ctx.line < 0:
                                 ctx = typ
                             self.fail(message_registry.FUNCTION_PARAMETER_CANNOT_BE_COVARIANT, ctx)
-                    elif (is_named_instance(arg_type, 'builtins.list')
+                    elif (isinstance(arg_type, Instance)
+                            and is_named_instance(arg_type, 'builtins.list')
                             and isinstance(self.iterable_item_type(arg_type), TypeVarType)):
                         if(self.iterable_item_type(arg_type).variance == COVARIANT):
                             message = "Cannot use a covariant type variable as a parameter"