From 0cb09f9a8b6853757d09abf19b333616d410aeb8 Mon Sep 17 00:00:00 2001
From: Kumar Aditya <kumaraditya@python.org>
Date: Wed, 1 Oct 2025 14:45:33 +0530
Subject: [PATCH 1/3] improve isolation of
 test_pending_call_creates_thread_subinterpreter

---
 Lib/test/test_capi/test_misc.py | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py
index 229a7c2afa8f8d..66f0f23bab79ad 100644
--- a/Lib/test/test_capi/test_misc.py
+++ b/Lib/test/test_capi/test_misc.py
@@ -1984,9 +1984,9 @@ def test_module_state_shared_in_global(self):
     @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
     @requires_subinterpreters
     def test_pending_call_creates_thread_subinterpreter(self):
-        interpreters = import_helper.import_module("concurrent.interpreters")
-        r, w = os.pipe()
+        # For better isolation, run the entire test in a different subprocess.
         source = f"""if True:
+        code = '''if True:
         import _testinternalcapi
         import threading
         import time
@@ -1995,9 +1995,7 @@ def test_pending_call_creates_thread_subinterpreter(self):
 
         def output():
             time.sleep(1)
-            os.write({w}, b"x")
-            os.close({w})
-
+            print("x")
 
         def callback():
             threading.Thread(target=output).start()
@@ -2007,15 +2005,19 @@ def create_pending_call():
             time.sleep(1)
             _testinternalcapi.simple_pending_call(callback)
 
-
         threading.Thread(target=create_pending_call).start()
-        """
+        '''
+
+        import concurrent.interpreters as interpreters
+
         interp = interpreters.create()
-        interp.exec(source)
+        interp.exec(code)
         interp.close()
-        data = os.read(r, 1)
-        self.assertEqual(data, b"x")
-        os.close(r)
+        """
+        rc, out, err = assert_python_ok('-c', source)
+        self.assertEqual(rc, 0)
+        self.assertEqual(out, b"x\n")
+        self.assertEqual(err, b"")
 
 
 @requires_subinterpreters

From 81f305fcd09719570c0848cb0ec93755b38f136f Mon Sep 17 00:00:00 2001
From: Kumar Aditya <kumaraditya@python.org>
Date: Wed, 1 Oct 2025 15:08:04 +0530
Subject: [PATCH 2/3] improve isolation of
 test_pending_call_creates_thread_subinterpreter

---
 Lib/test/test_capi/test_misc.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py
index 66f0f23bab79ad..3d36e7147a4e7d 100644
--- a/Lib/test/test_capi/test_misc.py
+++ b/Lib/test/test_capi/test_misc.py
@@ -1995,7 +1995,7 @@ def test_pending_call_creates_thread_subinterpreter(self):
 
         def output():
             time.sleep(1)
-            print("x")
+            print("x", end="")
 
         def callback():
             threading.Thread(target=output).start()
@@ -2016,7 +2016,7 @@ def create_pending_call():
         """
         rc, out, err = assert_python_ok('-c', source)
         self.assertEqual(rc, 0)
-        self.assertEqual(out, b"x\n")
+        self.assertEqual(out, b"x")
         self.assertEqual(err, b"")
 
 

From 792c27f6c7e2c633104aaf5c82ac73cfd3e8d148 Mon Sep 17 00:00:00 2001
From: Kumar Aditya <kumaraditya@python.org>
Date: Wed, 1 Oct 2025 17:24:31 +0530
Subject: [PATCH 3/3] remove marker

---
 Lib/test/test_capi/test_misc.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py
index 3d36e7147a4e7d..6f1bcbe8454eb8 100644
--- a/Lib/test/test_capi/test_misc.py
+++ b/Lib/test/test_capi/test_misc.py
@@ -1981,7 +1981,6 @@ def test_module_state_shared_in_global(self):
         self.assertEqual(main_attr_id, subinterp_attr_id)
 
     @threading_helper.requires_working_threading()
-    @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
     @requires_subinterpreters
     def test_pending_call_creates_thread_subinterpreter(self):
         # For better isolation, run the entire test in a different subprocess.