rust and python

[Jon Turney]

On 30/12/2025 11:49, Marco Atzeri via Cygwin-apps wrote:
> Hi Mantainers,
> 
> using the SCALLYWAG build of rust
> 
> $ rustc --version
> rustc 1.91.0 (f8297e351 2025-10-28) (built from a source tarball)
> 
> I was able to compile the latest versions of
> 
>      python-bcrypt
>      python-cryptography
> 
> that I uploded as TEST.
> 
> The build dependency on RUST is currently disabled to avoid complaint
> during the upload.
> 
> While "python-bcrypt" was relative straightward with minor trick to set 
> RUSTFLAGS for the right version of python
> 
> ---------------------------------------------------------
> BASE_PYTHON_WHEEL_VERSIONS=${PYTHON_WHEEL_VERSIONS}
> 
> src_compile() {
>          cd ${S}
>          lndirs
>          cd ${B}
>          for v in ${BASE_PYTHON_WHEEL_VERSIONS//:/ }
>          do
>                  export RUSTFLAGS=" -lpython${v}"
>                  PYTHON_WHEEL_VERSIONS="${v}"
>                  inform "building ${v}"
>                  python_wheel_compile
>          done
>          PYTHON_WHEEL_VERSIONS=${BASE_PYTHON_WHEEL_VERSIONS}

Huh. Interesting.

I guess that just means that something in the guts of the build doesn't 
realize that -lpythonNN is needed on cygwin (to complete undefined 
references in the library built).

> }
> ---------------------------------------------------------
> 
> "python-cryptography" needed an additional package
> as the wheel files were NOT in a suitable format
> 
> ./dist/cryptography-46.0.3-cp312-abi3-cygwin_86_64.whl
> ./dist/cryptography-46.0.3-cp39-abi3-cygwin_86_64.whl
> 
> after installing the "python-maturin" packages the wheel files
> were correctly built
> 
> ./dist/cryptography-46.0.3-cp312-abi3-cygwin_3_6_5_x86_64.whl
> ./dist/cryptography-46.0.3-cp39-abi3-cygwin_3_6_5_x86_64.whl

Hmm... coincidentally, I was recently looking at this logic [1] which 
recognizes .whl filenames

I'm not sure if the matching there is just ad-hoc, or what it means when 
python chooses to include the 'uname -r' ("kernel version") in the wheel 
filename.

[1] 
https://cygwin.com/cgit/cygwin-apps/cygport/tree/cygclass/python-wheel.cygclass#n193