[3.12] gh-107080: Fix Py_TRACE_REFS Crashes Under Isolated Subinterpreters (#107751)

* Unrevert "[3.12] gh-107080: Fix Py_TRACE_REFS Crashes Under Isolated Subinterpreters (gh-107567) (#107599)".

This reverts commit 6e4eec760648a71e1cd8f8f551997b1823b4bb9f (gh-107648).

* Initialize each interpreter's refchain properly.

* Skip test_basic_multiple_interpreters_deleted_no_reset on tracerefs builds.

1 files changed, 6 insertions, 0 deletions

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 06adf01..f7df6d7 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -2539,6 +2539,12 @@ class SinglephaseInitTests(unittest.TestCase):
     def test_basic_multiple_interpreters_deleted_no_reset(self):
         # without resetting; already loaded in a deleted interpreter
 
+        if hasattr(sys, 'getobjects'):
+            # It's a Py_TRACE_REFS build.
+            # This test breaks interpreter isolation a little,
+            # which causes problems on Py_TRACE_REF builds.
+            raise unittest.SkipTest('crashes on Py_TRACE_REFS builds')
+
         # At this point:
         #  * alive in 0 interpreters
         #  * module def may or may not be loaded already