From 2ffbe41ae526b5367fca798e405fceab9bc57228 Mon Sep 17 00:00:00 2001
From: Mark Dickinson <mdickinson@enthought.com>
Date: Thu, 21 Nov 2019 13:06:47 +0000
Subject: [PATCH] clear sys.last_traceback via del instead of = None

---
 src/_pytest/runner.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/_pytest/runner.py b/src/_pytest/runner.py
index c383146c3..67e28e905 100644
--- a/src/_pytest/runner.py
+++ b/src/_pytest/runner.py
@@ -121,7 +121,12 @@ def pytest_runtest_setup(item):
 
 def pytest_runtest_call(item):
     _update_current_test_var(item, "call")
-    sys.last_type, sys.last_value, sys.last_traceback = (None, None, None)
+    try:
+        del sys.last_type
+        del sys.last_value
+        del sys.last_traceback
+    except AttributeError:
+        pass
     try:
         item.runtest()
     except Exception: