Support Python 3.12

[EwoutH]

Python 3.12 is releasing in exactly one week, Monday 2023-10-02. It would be great if JPype could support Python 3.12 fully at the release, including testing in CI and wheels uploaded to PyPI.

Summary – Python 3.12 Release highlights

New grammar features:

• PEP 701: Syntactic formalization of f-strings

Interpreter improvements:

• PEP 684: A Per-Interpreter GIL
• PEP 669: Low impact monitoring for CPython

New typing features:

• PEP 688: Making the buffer protocol accessible in Python
• PEP 692: Using TypedDict for more precise **kwargs typing
• PEP 695: Type Parameter Syntax
• PEP 698: Override Decorator for Static Typing

Important deprecations, removals or restrictions:

• PEP 623: Remove wstr from Unicode
• PEP 632: Remove the distutils package. See the migration guide for advice on its replacement.
• gh-95299: Do not pre-install setuptools in virtual environments created with venv. This means that distutils, setuptools, pkg_resources, and easy_install will no longer available by default; to access these run pip install setuptools in the activated virtual environment.

[marscher]

Thanks. I'd welcome any PR fixing the issue with Python 3.12. Have a look at the details here:

• https://github.com/conda-forge/jpype1-feedstock/pull/50/checks

• https://dev.azure.com/conda-forge/feedstock-builds/_build/results?buildId=786512&view=logs&jobId=517fe804-fa30-5dc2-1413-330699242c05&j=517fe804-fa30-5dc2-1413-330699242c05&t=c7d0fcb4-3a10-5b26-dfea-e879a93fc2ab

[Christopher-Chianelli]

From the logs, it seems the issue is the change of location of ob_digit

  native/common/jp_primitivetype.cpp: In member function 'PyObject* JPPrimitiveType::convertLong(PyTypeObject*, PyLongObject*)':
  native/common/jp_primitivetype.cpp:50:25: error: 'PyLongObject' {aka 'struct _longobject'} has no member named 'ob_digit'
     50 |                 newobj->ob_digit[i] = tmp->ob_digit[i];
        |                         ^~~~~~~~
  native/common/jp_primitivetype.cpp:50:44: error: 'PyLongObject' {aka 'struct _longobject'} has no member named 'ob_digit'
     50 |                 newobj->ob_digit[i] = tmp->ob_digit[i];

According to cython/cython#5238 (comment) ; changing it to ((PyLongObject*)op1)->long_value->ob_digit should work.

[Christopher-Chianelli]

It more complicated than this, since wstr is now removed: https://www.python.org/dev/peps/pep-0623

[Thrameos]

I was able to fix both the wstr and ob_digit error, but they also broke the jp_value memory hack which adds extra memory to all types of us to store the extra bytes needs for the wrapper. As a result we are getting random segmentation faults when the memory between the two collides. (the absolute worst kind of error to fix.) They promised a replacement that should be in 3.12 though I am still searching.

[marscher]

fixed by #1158

[EwoutH]

Awesome, thanks a lot!

When can we expect a release and wheels on n PyPI?

[Thrameos]

Starting the process after fixing all merge requests.