From b837d0b8cf2a46a977e33b908f7036127b1cf9f4 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Mon, 17 Nov 2025 14:20:51 -0800
Subject: [PATCH 1/2] gh-141172: Update to wasi-sdk-29

This commit updates CI and configuration from wasi-sdk-25 to wasi-sdk-29
which was released recently. This notably includes stubs for pthreads
which all return errors, so some adjustment in logic is necessary to
retain knowledge that WASI cannot yet spawn threads for example.

This additionally increases the wasm stack allowance to 32MiB from 16MiB
to accomodate the `test_recursive_pickle` test in teh
`test_functools.py` file. It looks like the Clang/LLVM update that
happened in wasi-sdk-29 relative to wasi-sdk-25 is likely the cause of
this where presumably functions have more locals than before and/or a
slightly adjusted stack space requirement which overflows the stack.
---
 .github/workflows/reusable-wasi.yml | 2 +-
 Include/pyport.h                    | 1 +
 Lib/test/test_sys.py                | 4 +---
 Tools/wasm/wasi/__main__.py         | 6 +++---
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/reusable-wasi.yml b/.github/workflows/reusable-wasi.yml
index a309ef4e7f4485..91d76fd1b5f8c5 100644
--- a/.github/workflows/reusable-wasi.yml
+++ b/.github/workflows/reusable-wasi.yml
@@ -13,7 +13,7 @@ jobs:
     timeout-minutes: 60
     env:
       WASMTIME_VERSION: 38.0.3
-      WASI_SDK_VERSION: 25
+      WASI_SDK_VERSION: 29
       WASI_SDK_PATH: /opt/wasi-sdk
       CROSS_BUILD_PYTHON: cross-build/build
       CROSS_BUILD_WASI: cross-build/wasm32-wasip1
diff --git a/Include/pyport.h b/Include/pyport.h
index b250f9e308f2dd..97c0e195d19808 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -504,6 +504,7 @@ extern "C" {
  * Thread support is stubbed and any attempt to create a new thread fails.
  */
 #if (!defined(HAVE_PTHREAD_STUBS) && \
+     !defined(__wasi__) && \
       (!defined(__EMSCRIPTEN__) || defined(__EMSCRIPTEN_PTHREADS__)))
 #  define Py_CAN_START_THREADS 1
 #endif
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 2f169c1165df05..2e87e38fe5dfdc 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -730,14 +730,12 @@ def test_thread_info(self):
         self.assertEqual(len(info), 3)
         self.assertIn(info.name, ('nt', 'pthread', 'pthread-stubs', 'solaris', None))
         self.assertIn(info.lock, ('pymutex', None))
-        if sys.platform.startswith(("linux", "android", "freebsd")):
+        if sys.platform.startswith(("linux", "android", "freebsd", "wasi")):
             self.assertEqual(info.name, "pthread")
         elif sys.platform == "win32":
             self.assertEqual(info.name, "nt")
         elif sys.platform == "emscripten":
             self.assertIn(info.name, {"pthread", "pthread-stubs"})
-        elif sys.platform == "wasi":
-            self.assertEqual(info.name, "pthread-stubs")
 
     def test_abi_info(self):
         info = sys.abi_info
diff --git a/Tools/wasm/wasi/__main__.py b/Tools/wasm/wasi/__main__.py
index bb5ce30c5d8b4f..59ffd436258185 100644
--- a/Tools/wasm/wasi/__main__.py
+++ b/Tools/wasm/wasi/__main__.py
@@ -31,7 +31,7 @@
     b"# Required to statically build extension modules."
 )
 
-WASI_SDK_VERSION = 25
+WASI_SDK_VERSION = 29
 
 WASMTIME_VAR_NAME = "WASMTIME"
 WASMTIME_HOST_RUNNER_VAR = f"{{{WASMTIME_VAR_NAME}}}"
@@ -419,8 +419,8 @@ def main():
         f"{WASMTIME_HOST_RUNNER_VAR} run "
         # Make sure the stack size will work for a pydebug
         # build.
-        # Use 16 MiB stack.
-        "--wasm max-wasm-stack=16777216 "
+        # Use 32 MiB stack.
+        "--wasm max-wasm-stack=33554432 "
         # Enable thread support; causes use of preview1.
         # "--wasm threads=y --wasi threads=y "
         # Map the checkout to / to load the stdlib from /Lib.

From 073c26003b048a37dba6300d25cda010836f7647 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Wed, 19 Nov 2025 09:21:27 -0800
Subject: [PATCH 2/2] Add news entry

---
 .../next/Build/2025-11-19-09-21-17.gh-issue-141172.cYWc4x.rst    | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Build/2025-11-19-09-21-17.gh-issue-141172.cYWc4x.rst

diff --git a/Misc/NEWS.d/next/Build/2025-11-19-09-21-17.gh-issue-141172.cYWc4x.rst b/Misc/NEWS.d/next/Build/2025-11-19-09-21-17.gh-issue-141172.cYWc4x.rst
new file mode 100644
index 00000000000000..7cade1ebd414e3
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2025-11-19-09-21-17.gh-issue-141172.cYWc4x.rst
@@ -0,0 +1 @@
+Update to WASI SDK 29.