limited api wheels for 3.12+ with cython 3.1

.github/workflows/test.yml

@@ -25,6 +25,10 @@ concurrency:
 
 env:
   FORCE_COLOR: "1"
+  # only affects Windows, but easiest to set here for now
+  SETUPTOOLS_ENABLE_FEATURES: "legacy-editable"
+  # don't compile Cython if we are building from source
+  NO_CYTHON_COMPILE: "true"
 
 jobs:
   test:
@@ -71,10 +75,11 @@ jobs:
           - os: ubuntu-22.04
             python: "3.11"
             zmq: head
+            tornado: head
 
           - os: ubuntu-24.04
             python: "3.12"
-            tornado: head
+            abi: cp312
 
           - os: ubuntu-24.04
             python: "3.13"
@@ -124,9 +129,6 @@ jobs:
         if: ${{ matrix.free_threading }}
         run: |
           echo "PYTHON_GIL=0" >> "$GITHUB_ENV"
-          # need prerelease Cython until 3.1 is out
-          echo "PIP_PRE=1" >> "$GITHUB_ENV"
-          echo "PIP_EXTRA_INDEX_URL=https://pypi.anaconda.org/scientific-python-nightly-wheels/simple" >> "$GITHUB_ENV"
           echo "EXTRA_PIP=--no-binary coverage" >> "$GITHUB_ENV"
 
       - name: setup coverage
@@ -187,6 +189,11 @@ jobs:
           echo "PYZMQ_BACKEND=${{ matrix.backend }}" >> "$GITHUB_ENV"
           pip install cffi
 
+      - name: set stable ABI
+        if: matrix.abi
+        run: |
+          echo "PIP_CONFIG_SETTINGS=wheel.py-api=${{ matrix.abi }}" >> "$GITHUB_ENV"
+
       - name: install libzmq-dev
         if: matrix.zmq == 'head'
         run: |

CMakeLists.txt

@@ -5,13 +5,13 @@ set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
 list(PREPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 find_package(
   Python
-  COMPONENTS Interpreter Development.Module
+  COMPONENTS Interpreter Development.Module ${SKBUILD_SABI_COMPONENT}
   REQUIRED)
 
 # Python_SOABI isn't always right when cross-compiling
 # SKBUILD_SOABI seems to be
 if (DEFINED SKBUILD_SOABI AND NOT "${SKBUILD_SOABI}" STREQUAL "${Python_SOABI}")
-  message(WARNING "SKBUILD_SOABI=${SKBUILD_SOABI} != Python_SOABI=${Python_SOABI}; likely cross-compiling, using SOABI=${SKBUILD_SOABI} from scikit-build")
+  message(WARNING "SKBUILD_SOABI=${SKBUILD_SOABI} != Python_SOABI=${Python_SOABI}; likely cross-compiling or Limited API, using SOABI=${SKBUILD_SOABI} from scikit-build")
   set(Python_SOABI "${SKBUILD_SOABI}")
 endif()
 
@@ -431,9 +431,16 @@ endif()
 
 file(MAKE_DIRECTORY ${ZMQ_BACKEND_DEST})
 
+if(NOT "${SKBUILD_SABI_COMPONENT}" STREQUAL "")
+  # set stable ABI
+  set(SABI_ARG "USE_SABI;${SKBUILD_SABI_VERSION}")
+  message(STATUS "Building with stable ABI ${Python_SOABI} for ${SKBUILD_SABI_VERSION}")
+endif()
+
 python_add_library(
   ${ZMQ_EXT_NAME} MODULE
   WITH_SOABI
+  ${SABI_ARG}
   ${ZMQ_C}
 )
 

pyproject.toml

@@ -62,6 +62,11 @@ install.components = ["pyzmq"]
 if.env.PYZMQ_BACKEND = "cffi"
 build.requires = ["cffi"]
 
+[[tool.scikit-build.overrides]]
+if.any.env.PYZMQ_LATEST_CYTHON = true
+build.requires = ["cython @ https://github.com/cython/cython/archive/HEAD.tar.gz"]
+
+
 [tool.ruff]
 
 [tool.ruff.format]
@@ -149,6 +154,10 @@ build-verbosity = "1"
 enable = ["cpython-freethreading", "pypy"]
 test-requires = ["pytest>=6", "importlib_metadata"]
 test-command = "pytest -vsx {package}/tools/test_wheel.py"
+build-frontend = "build"
+
+[tool.cibuildwheel.environment]
+NO_CYTHON_COMPILE = "true"
 
 [tool.cibuildwheel.linux]
 before-all = "bash tools/install_libzmq.sh"
@@ -195,16 +204,20 @@ repair-wheel-command = """\
 "cmake.define.ZMQ_HAVE_IPC" = "OFF"
 "cmake.define.POLLER" = "select"
 
-
 # manylinux2010 for (less) old cp37-9, pp37-8
 [[tool.cibuildwheel.overrides]]
 select = "cp3{7,8,9}-* pp3{7,8}-*"
 manylinux-x86_64-image = "manylinux2010"
 manylinux-i686-image = "manylinux2010"
 
+# build limited-api wheels for 3.12
+[[tool.cibuildwheel.overrides]]
+select = "cp312-*"
+inherit.config-settings = "append"
+config-settings."wheel.py-api" = "cp312"
+before-build = "pip install abi3audit"
+inherit.repair-wheel-command = "append"
+repair-wheel-command = "abi3audit --strict --report {wheel}"
+
 # note: manylinux_2_28 builds are added
 # in .github/workflows/wheels.yml
-
-[[tool.cibuildwheel.overrides]]
-select = "cp313t-*"
-build-frontend = "pip; args: -v --pre --extra-index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple"

tools/wheel-requirements.txt

@@ -1,2 +1,3 @@
+abi3audit
 cibuildwheel==2.23.*
 delvewheel==1.10.*; sys_platform == 'win32'