Integrate yaml/pyyaml#602

ports/py-pyyaml/cython.patch

@@ -0,0 +1,38 @@
+From 3237b4074243704a9cce41dbf6dc14a2a2d4d78e Mon Sep 17 00:00:00 2001
+From: Matt Davis <[email protected]>
+Date: Wed, 12 Jan 2022 15:29:48 -0800
+Subject: [PATCH] WIP keep PyYAML build working on Cython3.0.0a10+
+
+* Cython 3.0 changes its build_ext command base class to one that's incompatible with pyyaml's subclass
+* temporarily force use of Cython3's `old_build_ext` compatibility class if present
+---
+ pyproject.toml | 2 +-
+ setup.py       | 6 +++++-
+ 2 files changed, 6 insertions(+), 2 deletions(-)
+
+diff --git a/pyproject.toml b/pyproject.toml
+index 2bf5ec80..3cf9a28d 100644
+--- a/pyproject.toml
++++ b/pyproject.toml
+@@ -1,3 +1,3 @@
+ [build-system]
+-requires = ["setuptools", "wheel", "Cython"]
++requires = ["setuptools", "wheel", "Cython~=3.0a"]
+ build-backend = "setuptools.build_meta"
+diff --git a/setup.py b/setup.py
+index 548b19f7..da4a66fa 100644
+--- a/setup.py
++++ b/setup.py
+@@ -81,7 +81,11 @@
+     with_cython = True
+ try:
+     from Cython.Distutils.extension import Extension as _Extension
+-    from Cython.Distutils import build_ext as _build_ext
++
++    try:
++        from Cython.Distutils.old_build_ext import old_build_ext as _build_ext
++    except ImportError:
++        from Cython.Distutils import build_ext as _build_ext
+     with_cython = True
+ except ImportError:
+     if with_cython:

ports/py-pyyaml/portfile.cmake

@@ -3,6 +3,8 @@ vcpkg_from_pythonhosted(
     PACKAGE_NAME    PyYAML
     VERSION         ${VERSION}
     SHA512          94a29924484f557c0966d485c2b70232909253f27fcea9b89e1db1462abf61f2f85d55fbae0177b2bed70eb5daa75813551e868df4df4cddfdee9a87bd08485f
+    PATCHES
+        cython.patch
 )
 
 vcpkg_python_build_and_install_wheel(SOURCE_PATH "${SOURCE_PATH}" OPTIONS -x)