From f3316ca675fada57bdf862d7e3aebfd6bb5ac02c Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Thu, 11 Jun 2026 08:38:03 +0200
Subject: [PATCH] [3.15] gh-136880: Add warning about PYTHONPATH (GH-151098)
 (GH-151299)

(cherry picked from commit 84630e2cb90ef334e41eb9bccd860b3b0a7ff51b)
---
 Doc/tutorial/venv.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Doc/tutorial/venv.rst b/Doc/tutorial/venv.rst
index f362e1943b66..6b6b8a768e3f 100644
--- a/Doc/tutorial/venv.rst
+++ b/Doc/tutorial/venv.rst
@@ -88,6 +88,11 @@ For example:
   '~/envs/tutorial-env/lib/python3.5/site-packages']
   >>>
 
+Note that the activated virtual environment does not alter the ``PYTHONPATH`` variable in any way.
+This may lead to unexpected results if the path includes references to code which is incompatible with
+the Python version the virtual environment is using. The best practice is to ``unset PYTHONPATH``
+in bash or the equivalent for the shell you are using.
+
 To deactivate a virtual environment, type::
 
     deactivate
-- 
2.47.3