Compiling Cython code

[x1mus]

I am trying to compile a python mobule (C code generated with cython) but I am facing an issue while compiling.

I have extended the Dockcross image as specified in the README:

FROM dockcross/android-x86_64

ENV DEFAULT_DOCKCROSS_IMAGE dockcross/py-android-x86_64

RUN apt-get install -y python3

The compilation command is the following:

$ ./dockcross-py-android-x86_64 bash -c '$CC -g -shared -pthread -fPIC -fwrapv -Wall -fno-strict-aliasing -I/usr/include/python3.11 -o hello.so hello.c'
In file included from hello.c:6:
In file included from /usr/include/python3.11/Python.h:12:
/usr/include/python3.11/pyconfig.h:3:12: fatal error: 'x86_64-linux-gnu/python3.11/pyconfig.h' file not found
#  include <x86_64-linux-gnu/python3.11/pyconfig.h>
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

However, pyconfig.h is actually present in the docker when verifying it manually. I also tried to add python3-dev which doesn't change anything since python-dev-is-python3. Also adding libraries mentioned across other issues related to this but didn't fix the issue.

[thewtex]

Hi,

RUN apt-get install -y python3
/usr/include/python3.11/pyconfig.h

This is building against python for the host system, not the target system, which is not what you want.

To build python for the target system, see

• https://github.com/dockcross/dockcross/blob/master/.github/workflows/main.yml#L1174-L1179

or

• https://github.com/python-cmake-buildsystem/python-cmake-buildsystem

For cross-compling cython, we are considering a hackathon at the SciPy conference this summer to improve support in scikit-build-core.

[x1mus]

Thanks for the clarification. If I understood correctly installing python3 for the target machine can be achieved by modifying the main workflow but compiling cython (for android in my case) isn't available right now ?

[thewtex]

Cross-compiling Cython with dockcross is not well tested yet.

CC @jcfr @henryiii

[x1mus]

Is there any way to get the experimental branch running for testing purposes by any chance ?

[thewtex]

scikit-build-core main could be tested. Cython support was improved recently. There are likely issues cross-compiling as discussed here: https://github.com/orgs/scikit-build/discussions/1077