From 2a1e48fabcc696ade1aac9ac6c6c4a4fc980e365 Mon Sep 17 00:00:00 2001
From: don012rac3 <don012rac3@users.noreply.github.com>
Date: Sat, 5 Sep 2026 21:21:20 +0000
Subject: [PATCH] gh-157006: Clear PYTHONSTARTUP and other PYTHON* env vars in
 test_embed

run_embedded_interpreter() now defaults to remove_python_envvars()
when no explicit env is provided, preventing PYTHONSTARTUP (e.g.,
set by VS Code shell integration) from leaking into the embedded
interpreter and causing test failures.

Also fix test_init_run_main_startup_exitcode to use
remove_python_envvars() instead of dict(os.environ) as the base
environment.
---
 Lib/test/test_embed.py                                        | 4 +++-
 .../next/Tests/2026-09-06-12-00-00.gh-issue-157006.Xk9mPq.rst | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Tests/2026-09-06-12-00-00.gh-issue-157006.Xk9mPq.rst

diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index 1ff600e30bf4cbd..ada9f4e29921805 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -137,6 +137,8 @@ def run_embedded_interpreter(self, *args, env=None,
         """Runs a test in the embedded interpreter"""
         cmd = [self.test_exe]
         cmd.extend(args)
+        if env is None:
+            env = remove_python_envvars()
         if env is not None and MS_WINDOWS:
             # Windows requires at least the SYSTEMROOT environment variable to
             # start Python.
@@ -628,7 +630,7 @@ def test_init_run_main_startup_exitcode(self):
             with open(filename, 'x') as fp:
                 fp.write(CODE_EXITCODE_123)
 
-            env = dict(os.environ)
+            env = remove_python_envvars()
             env['PYTHONSTARTUP'] = filename
             self.check_program_exitcode("test_init_run_main_interactive_exitcode",
                                         env=env,
diff --git a/Misc/NEWS.d/next/Tests/2026-09-06-12-00-00.gh-issue-157006.Xk9mPq.rst b/Misc/NEWS.d/next/Tests/2026-09-06-12-00-00.gh-issue-157006.Xk9mPq.rst
new file mode 100644
index 000000000000000..7e6b3db296dc41b
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-09-06-12-00-00.gh-issue-157006.Xk9mPq.rst
@@ -0,0 +1,4 @@
+Fix ``test.test_embed`` to clear ``PYTHON*`` environment variables (including
+``PYTHONSTARTUP``) before running embedded interpreter tests, preventing failures
+when the test runner's environment has these variables set (e.g., by VS Code's
+shell integration).