Python 3.13 compatibility

[nitzmahone]

fixes #23

• updates obsolete private API aliases removed in 3.13
• make unraisable tests less brittle to traceback formatting changes across Python versions

Full test suite passes locally on 3.13.0a1 under Linux x86_64 with these changes.

[alex]

First commit LGTM. I didn't review teh 2nd commit closely.

[hroncok]

With -Werror=implicit-function-declaration and Python 3.13.0a1 I get:

      src/c/_cffi_backend.c: In function ‘_my_PyLong_AsUnsignedLongLong’:
      src/c/_cffi_backend.c:868:17: error: implicit declaration of function ‘_PyLong_Sign’ [-Werror=implicit-function-declaration]
        868 |             if (_PyLong_Sign(ob) < 0)
            |                 ^~~~~~~~~~~~
      src/c/_cffi_backend.c: In function ‘cdata_hash’:
      src/c/_cffi_backend.c:2449:12: error: implicit declaration of function ‘_Py_HashPointer’ [-Werror=implicit-function-declaration]
       2449 |     return _Py_HashPointer(((CDataObject *)v)->c_data);
            |            ^~~~~~~~~~~~~~~
      src/c/_cffi_backend.c: In function ‘b_do_dlopen’:
      src/c/_cffi_backend.c:4532:22: warning: ‘Py_FileSystemDefaultEncoding’ is deprecated [-Wdeprecated-declarations]
       4532 |                      Py_FileSystemDefaultEncoding, &filename_or_null, &flags))
            |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      In file included from /usr/include/python3.13/Python.h:77,
                       from src/c/_cffi_backend.c:2:
      /usr/include/python3.13/fileobject.h:22:46: note: declared here
         22 | Py_DEPRECATED(3.12) PyAPI_DATA(const char *) Py_FileSystemDefaultEncoding;
            |                                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      src/c/_cffi_backend.c: In function ‘_my_PyErr_WriteUnraisable’:
      src/c/_cffi_backend.c:6121:9: error: implicit declaration of function ‘_PyErr_WriteUnraisableMsg’; did you mean ‘PyErr_WriteUnraisable’? [-Werror=implicit-function-declaration]
       6121 |         _PyErr_WriteUnraisableMsg(PyText_AS_UTF8(s), NULL);
            |         ^~~~~~~~~~~~~~~~~~~~~~~~~
            |         PyErr_WriteUnraisable
      In file included from src/c/cffi1_module.c:15,
                       from src/c/_cffi_backend.c:7976:
      src/c/ffi_obj.c: In function ‘ffi_getctype’:
      src/c/ffi_obj.c:635:36: error: implicit declaration of function ‘isspace’ [-Werror=implicit-function-declaration]
        635 |     while (replace_with[0] != 0 && isspace(replace_with[0]))
            |                                    ^~~~~~~
      src/c/ffi_obj.c:1:1: note: include ‘<ctype.h>’ or provide a declaration of ‘isspace’
        +++ |+#include <ctype.h>
          1 |

Without -Werror=implicit-function-declaration, the thing builds, but I am unsure if it is built correctly. Running the tests with pytest to check.

[hroncok]

1951 passed, 89 skipped, 4 xfailed, 367 warnings

[hroncok]

Testing the update unraisable tests to use sys.unraisablehook together with 49127c6 on the recent Python 3.13 git HEAD.

[hroncok]

tests passed, trying to build cryptography

[hroncok]

cryptography build succeeded as well

[mindflayer]

Could you please release a new version with this fix?
It looks like a blocking issue for being able to add support for Python 3.13, impacting several packages.

[edgarrmondragon]

Could you please release a new version with this fix?
It looks like a blocking issue for being able to add support for Python 3.13, impacting several packages.

@mindflayer 1.17.0rc1 supports Python 3.13

[mindflayer]

Thank you @edgarrmondragon for sharing it. Do you happen to know when a stable one will be published?

[edgarrmondragon]

Thank you @edgarrmondragon for sharing it. Do you happen to know when a stable one will be published?

@mindflayer according to #71 (comment), the final release will be tagged soon after 3.13.0rc1 comes out. So some time after 2024-07-30.