GH-141509: Fix warning about remaining subinterpreters (GH-141528)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

Lib/test/test_interpreters/test_api.py

@@ -432,7 +432,7 @@ class InterpreterObjectTests(TestBase):
         exit()"""
         stdout, stderr = repl.communicate(script)
         self.assertIsNone(stderr)
-        self.assertIn(b"remaining subinterpreters", stdout)
+        self.assertIn(b"Interpreter.close()", stdout)
         self.assertNotIn(b"Traceback", stdout)
 
     @support.requires_subprocess()

Misc/NEWS.d/next/Core_and_Builtins/2025-11-14-00-19-45.gh-issue-141528.VWdax1.rst

@@ -0,0 +1,3 @@
+Suggest using :meth:`concurrent.interpreters.Interpreter.close` instead of the
+private ``_interpreters.destroy`` function when warning about remaining subinterpreters.
+Patch by Sergey Miryanov.

Python/pylifecycle.c

@@ -2643,7 +2643,7 @@ finalize_subinterpreters(void)
     (void)PyErr_WarnEx(
             PyExc_RuntimeWarning,
             "remaining subinterpreters; "
-            "destroy them with _interpreters.destroy()",
+            "close them with Interpreter.close()",
             0);
 
     /* Swap out the current tstate, which we know must belong