Add Py 3.15; make both API versions of getcurrent() consistent in raising RuntimeError during shutdown.

Author: jamadden

.github/workflows/tests.yml

@@ -29,6 +29,8 @@ jobs:
           - "3.13"
           - "3.14"
           - "3.14t"
+          - "3.15-dev"
+          - "3.15t-dev"
 
         # Recall the macOS and windows builds upload built wheels so all supported versions
         # need to run on mac.
@@ -99,7 +101,8 @@ jobs:
         ARCHFLAGS: "-arch x86_64 -arch arm64"
 
     - name: Check greenlet build
-      if: ${{ ! startsWith(runner.os, 'Windows') }}
+      # 3.15b1 has a problem with readme renderer, ModuleNotFoundError: No module named 'nh3.nh3'
+      if: ${{ !startsWith(runner.os, 'Windows') && !endsWith(matrix.python-version, '-dev')}}
       run: |
         ls -l dist
         twine check dist/*

CHANGES.rst

@@ -5,7 +5,16 @@
 3.5.1 (unreleased)
 ==================
 
-- Nothing changed yet.
+- Add preliminary support for Python 3.15b1. This has not been
+  reviewed by CPython core developers, but all tests pass. Binary
+  wheels of this version won't work on earlier Python 3.15 builds and
+  may not work on later 3.15 builds.
+- Fix the discrepancy in the way the two ``getcurrent`` APIs behave
+  during greenlet teardown. One API (the C API used by, e.g.,  gevent) raised a
+  ``RuntimeError``; the other (the Python ``greenlet.getcurrent`` API)
+  returned ``None``. This second way breaks greenlet's type
+  annotations, so ``greenlet.getcurrent`` now raises a
+  ``RuntimeError`` as well.
 
 
 3.5.0 (2026-04-27)

make-manylinux

@@ -41,7 +41,7 @@ if [ -d /greenlet -a -d /opt/python ]; then
     which auditwheel
     echo "Installed Python versions"
     ls -l /opt/python
-    for variant in  /opt/python/cp{314,313,312,311,310}*; do
+    for variant in  /opt/python/cp{315,314,313,312,311,310}*; do
         if [[ "$variant" == *3t ]]; then
             echo "Skipping no-gil build for 3.13; only 3.14 is fully supported."
             continue

pyproject.toml

@@ -31,6 +31,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
     "Operating System :: OS Independent",
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]

src/greenlet/PyModule.cpp

@@ -28,7 +28,8 @@ static PyObject*
 mod_getcurrent(PyObject* UNUSED(module))
 {
     if (greenlet::IsShuttingDown()) {
-        Py_RETURN_NONE;
+        PyErr_SetString(PyExc_RuntimeError, "greenlet is being finalized");
+        return nullptr;
     }
     return GET_THREAD_STATE().state().get_current().relinquish_ownership_o();
 }

src/greenlet/tests/test_interpreter_shutdown.py

@@ -532,7 +532,7 @@ def create_at_exit():
     # -----------------------------------------------------------------
 
     def test_getcurrent_returns_none_during_gc_finalization(self):
-        # greenlet.getcurrent() must return None when called from a
+        # greenlet.getcurrent() must raise an exception when called from a
         # __del__ method during Py_FinalizeEx's GC collection pass.
 
         # On Python >= 3.11, _Py_IsFinalizing() is True during this
@@ -549,8 +549,9 @@ def test_getcurrent_returns_none_during_gc_finalization(self):
             class CleanupChecker:
                 def __del__(self):
                     try:
-                        cur = greenlet.getcurrent()
-                        if cur is None:
+                        try:
+                            greenlet.getcurrent()
+                        except RuntimeError:
                             os.write(1, b"GUARDED: getcurrent=None\\n")
                         else:
                             os.write(1, b"UNGUARDED: getcurrent="
@@ -568,9 +569,7 @@ def __del__(self):
         """)
         self.assertEqual(rc, 0, f"Process crashed (rc={rc}):\n{stdout}{stderr}")
         self.assertIn("OK: deferred cycle created", stdout)
-        self.assertIn("GUARDED: getcurrent=None", stdout,
-                      "getcurrent() must return None during GC finalization; "
-                      "returned a live object instead (missing Py_IsFinalizing guard)")
+        self.assertIn("GUARDED: getcurrent=None", stdout)
 
     def test_getcurrent_returns_none_during_gc_finalization_with_active_greenlets(self):
         # Same as above but with active greenlets at shutdown, which
@@ -586,8 +585,9 @@ def test_getcurrent_returns_none_during_gc_finalization_with_active_greenlets(se
             class CleanupChecker:
                 def __del__(self):
                     try:
-                        cur = greenlet.getcurrent()
-                        if cur is None:
+                        try:
+                            greenlet.getcurrent()
+                        except RuntimeError:
                             os.write(1, b"GUARDED: getcurrent=None\\n")
                         else:
                             os.write(1, b"UNGUARDED: getcurrent="
@@ -614,9 +614,7 @@ def worker():
         """)
         self.assertEqual(rc, 0, f"Process crashed (rc={rc}):\n{stdout}{stderr}")
         self.assertIn("OK: 10 active greenlets, cycle deferred", stdout)
-        self.assertIn("GUARDED: getcurrent=None", stdout,
-                      "getcurrent() must return None during GC finalization; "
-                      "returned a live object instead (missing Py_IsFinalizing guard)")
+        self.assertIn("GUARDED: getcurrent=None", stdout)
 
     def test_getcurrent_returns_none_during_gc_finalization_cross_thread(self):
         # Combines cross-thread greenlet deallocation (deleteme list)
@@ -636,8 +634,9 @@ def test_getcurrent_returns_none_during_gc_finalization_cross_thread(self):
             class CleanupChecker:
                 def __del__(self):
                     try:
-                        cur = greenlet.getcurrent()
-                        if cur is None:
+                        try:
+                            greenlet.getcurrent()
+                        except RuntimeError:
                             os.write(1, b"GUARDED: getcurrent=None\\n")
                         else:
                             os.write(1, b"UNGUARDED: getcurrent="
@@ -669,9 +668,7 @@ def body():
         """)
         self.assertEqual(rc, 0, f"Process crashed (rc={rc}):\n{stdout}{stderr}")
         self.assertIn("OK: cross-thread cleanup + cycle deferred", stdout)
-        self.assertIn("GUARDED: getcurrent=None", stdout,
-                      "getcurrent() must return None during GC finalization; "
-                      "returned a live object instead (missing Py_IsFinalizing guard)")
+        self.assertIn("GUARDED: getcurrent=None", stdout)
 
 
     # -----------------------------------------------------------------

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py{310,311,312,313,314},docs,py314t,tsan-314,tsan-314t
+    py{310,311,312,313,314,315},docs,py314t,py315t,tsan-314,tsan-314t
 
 [testenv]
 commands =