From 395edd9c8f055005922b8e66a21ba9f0d2a7c2fd Mon Sep 17 00:00:00 2001
From: Karolina Surma <ksurma@redhat.com>
Date: Thu, 24 Feb 2022 09:38:54 +0100
Subject: [PATCH] Isolate spawned processes by unsetting PYTHONPATH

---
 setuptools/tests/environment.py | 5 +++++
 setuptools/tests/fixtures.py    | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/setuptools/tests/environment.py b/setuptools/tests/environment.py
index a0c0ec6..b0eac3a 100644
--- a/setuptools/tests/environment.py
+++ b/setuptools/tests/environment.py
@@ -18,6 +18,11 @@ class VirtualEnv(jaraco.envs.VirtualEnv):
     def run(self, cmd, *args, **kwargs):
         cmd = [self.exe(cmd[0])] + cmd[1:]
         kwargs = {"cwd": self.root, **kwargs}  # Allow overriding
+        if "env" not in kwargs:
+            env = dict(os.environ)
+            if "PYTHONPATH" in env:
+                del env["PYTHONPATH"]
+            kwargs["env"] = env
         return subprocess.check_output(cmd, *args, **kwargs)
 
 
diff --git a/setuptools/tests/fixtures.py b/setuptools/tests/fixtures.py
index 7599e65..d61ffa4 100644
--- a/setuptools/tests/fixtures.py
+++ b/setuptools/tests/fixtures.py
@@ -98,7 +98,8 @@ def venv(tmp_path, setuptools_wheel):
     env = environment.VirtualEnv()
     env.root = path.Path(tmp_path / 'venv')
     env.req = str(setuptools_wheel)
-    return env.create()
+    with contexts.environment(PYTHONPATH=None):
+        return env.create()
 
 
 @pytest.fixture
-- 
2.35.1