From 86d58113e52c8331ef83fd5849019c5422d7e62b Mon Sep 17 00:00:00 2001
From: Pascal Corpet <pcorpet@users.noreply.github.com>
Date: Mon, 23 Nov 2020 18:46:33 +0100
Subject: [PATCH] PYTHON-2438 Fix str representation of BulkWriteError (#522)

---
 pymongo/errors.py   | 5 +++--
 test/test_errors.py | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/pymongo/errors.py b/pymongo/errors.py
index ba6fec587..fd55226ab 100644
--- a/pymongo/errors.py
+++ b/pymongo/errors.py
@@ -240,8 +240,9 @@ class BulkWriteError(OperationFailure):
     def __init__(self, results):
         super(BulkWriteError, self).__init__(
             "batch op errors occurred", 65, results)
-        # For pickle support
-        self.args = (results,)
+
+    def __reduce__(self):
+        return self.__class__, (self.details,)
 
 
 class InvalidOperation(PyMongoError):
diff --git a/test/test_errors.py b/test/test_errors.py
index 5829d01de..968c8ebd7 100644
--- a/test/test_errors.py
+++ b/test/test_errors.py
@@ -93,6 +93,7 @@ class TestErrors(PyMongoTestCase):
     def test_pickle_BulkWriteError(self):
         exc = BulkWriteError({})
         self.assertOperationFailureEqual(exc, pickle.loads(pickle.dumps(exc)))
+        self.assertIn("batch op errors occurred", str(exc))
 
     def test_pickle_EncryptionError(self):
         cause = OperationFailure('error', code=5, details={},