build: enable free-threading compatibility

Author: cpcloud

cuda_bindings/setup.py

@@ -329,7 +329,7 @@ def do_cythonize(extensions):
     return cythonize(
         extensions,
         nthreads=nthreads,
-        compiler_directives=dict(language_level=3, embedsignature=True, binding=True),
+        compiler_directives=dict(language_level=3, embedsignature=True, binding=True, freethreading_compatible=True),
         **extra_cythonize_kwargs,
     )
 

cuda_core/build_hooks.py

@@ -101,7 +101,7 @@ def get_cuda_paths():
         verbose=True,
         language_level=3,
         nthreads=nthreads,
-        compiler_directives={"embedsignature": True, "warn.deprecated.IF": False},
+        compiler_directives={"embedsignature": True, "warn.deprecated.IF": False, "freethreading_compatible": True},
         compile_time_env=compile_time_env,
     )
 

cuda_core/pyproject.toml

@@ -51,7 +51,7 @@ cu12 = ["cuda-bindings[all]==12.*"]
 cu13 = ["cuda-bindings[all]==13.*"]
 
 [dependency-groups]
-test = ["cython>=3.0", "setuptools", "pytest>=6.2.4"]
+test = ["cython>=3.1", "setuptools", "pytest>=6.2.4"]
 test-cu12 = ["cuda-core[test]", "cupy-cuda12x; python_version < '3.14'", "cuda-toolkit[cudart]==12.*"]  # runtime headers needed by CuPy
 test-cu13 = ["cuda-core[test]", "cupy-cuda13x; python_version < '3.14'", "cuda-toolkit[cudart]==13.*"]  # runtime headers needed by CuPy
 # free threaded build, cupy doesn't support free-threaded builds yet, so avoid installing it for now