Unable to install C extension in 3.13t free threaded #856
Description
Python 3.13.3 free threaded version fails to compile the C extensions for pyyaml.
Installing with:
# pip install -v --no-build-isolation pyyaml
You get the following error:
BUILDING CYTHON EXT; self.include_dirs=['/usr/local/include/python3.13t'] self.library_dirs=['/usr/local/lib'] self.define=None
building 'yaml._yaml' extension
creating build/temp.linux-x86_64-cpython-313t/yaml
gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -fPIC -I/usr/local/include/python3.13t -c yaml/_yaml.c -o build/temp.linux-x86_64-cpython-313t/yaml/_yaml.o
yaml/_yaml.c:2155:80: error: unknown type name ‘__pyx_vectorcallfunc’; did you mean ‘vectorcallfunc’?
2155 | static CYTHON_INLINE PyObject *__Pyx_PyVectorcall_FastCallDict(PyObject *func, __pyx_vectorcallfunc vc, PyObject *const *args, size_t nargs, PyObject *kw);
| ^~~~~~~~~~~~~~~~~~~~
| vectorcallfunc
yaml/_yaml.c:29665:69: error: unknown type name ‘__pyx_vectorcallfunc’; did you mean ‘vectorcallfunc’?
29665 | static PyObject *__Pyx_PyVectorcall_FastCallDict_kw(PyObject *func, __pyx_vectorcallfunc vc, PyObject *const *args, size_t nargs, PyObject *kw)
| ^~~~~~~~~~~~~~~~~~~~
| vectorcallfunc
yaml/_yaml.c:29710:80: error: unknown type name ‘__pyx_vectorcallfunc’; did you mean ‘vectorcallfunc’?
29710 | static CYTHON_INLINE PyObject *__Pyx_PyVectorcall_FastCallDict(PyObject *func, __pyx_vectorcallfunc vc, PyObject *const *args, size_t nargs, PyObject *kw)
| ^~~~~~~~~~~~~~~~~~~~
| vectorcallfunc
yaml/_yaml.c: In function ‘__Pyx_CyFunction_CallAsMethod’:
yaml/_yaml.c:30399:6: error: unknown type name ‘__pyx_vectorcallfunc’; did you mean ‘vectorcallfunc’?
30399 | __pyx_vectorcallfunc vc = __Pyx_CyFunction_func_vectorcall(cyfunc);
| ^~~~~~~~~~~~~~~~~~~~
| vectorcallfunc
yaml/_yaml.c:2245:45: warning: initialization of ‘int’ from ‘vectorcallfunc’ {aka ‘struct _object * (*)(struct _object *, struct _object * const*, long unsigned int, struct _object *)’} makes integer from pointer without a cast [-Wint-conversion]
2245 | #define __Pyx_CyFunction_func_vectorcall(f) (((PyCFunctionObject*)f)->vectorcall)
| ^
yaml/_yaml.c:30399:32: note: in expansion of macro ‘__Pyx_CyFunction_func_vectorcall’
30399 | __pyx_vectorcallfunc vc = __Pyx_CyFunction_func_vectorcall(cyfunc);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
yaml/_yaml.c:30402:16: warning: implicit declaration of function ‘__Pyx_PyVectorcall_FastCallDict’; did you mean ‘__Pyx_PyObject_FastCallDict’? [-Wimplicit-function-declaration]
30402 | return __Pyx_PyVectorcall_FastCallDict(func, vc, &PyTuple_GET_ITEM(args, 0), (size_t)PyTuple_GET_SIZE(args), kw);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| __Pyx_PyObject_FastCallDict
yaml/_yaml.c:30402:16: warning: returning ‘int’ from a function with return type ‘PyObject *’ {aka ‘struct _object *’} makes pointer from integer without a cast [-Wint-conversion]
30402 | return __Pyx_PyVectorcall_FastCallDict(func, vc, &PyTuple_GET_ITEM(args, 0), (size_t)PyTuple_GET_SIZE(args), kw);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Error compiling module, falling back to pure Python
Installing the binary version does not include them either:
# pip install -v --no-build-isolation pyyaml --only-binary=wheel
>>> from pyyaml import CSafeLoader
Traceback (most recent call last):
File "<python-input-0>", line 1, in <module>
from pyyaml import CSafeLoader
ModuleNotFoundError: No module named 'pyyaml'
>>> from yaml import CSafeLoader
Traceback (most recent call last):
File "<python-input-1>", line 1, in <module>
from yaml import CSafeLoader
ImportError: cannot import name 'CSafeLoader' from 'yaml' (/usr/local/lib/python3.13t/site-packages/yaml/__init__.py). Did you mean: 'SafeLoader'?
Have the following versions installed:
root@ebc84fd57817:/# pip freeze | egrep -ie 'cython|setuptools'
Cython==3.0.12
setuptools==78.1.0
root@ebc84fd57817:/# pip --version
pip 25.0.1 from /usr/local/lib/python3.13t/site-packages/pip (python 3.13)
root@ebc84fd57817:/# python3 --version
Python 3.13.3
root@ebc84fd57817:/# python
Python 3.13.3 experimental free-threading build (main, Apr 15 2025, 18:16:12) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
root@ebc84fd57817:/# apt list | grep libyaml
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
libyaml-0-2/now 0.2.5-1 amd64 [installed,local]
libyaml-dev/now 0.2.5-1 amd64 [installed,local]
Using 3.13 standard, this works perfectly from a binary wheel and also compiling from source.
root@3cab962f6856:/# python3
Python 3.13.3 (main, Apr 9 2025, 00:27:54) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from yaml import CSafeLoader
>>> CSafeLoader
<class 'yaml.cyaml.CSafeLoader'>
