pyscipopt does not work with Python 3.11

[dimpase]

Is there an existing issue for this?

• I have searched the existing issues for a bug report that matches the one I want to file, without success.

Did you read the documentation and troubleshoot guide?

• I have read the documentation and troubleshoot guide

Environment

- **any OS**:
- **Sage with Python 11**:

Steps To Reproduce

Building: make pyscipopt fails with Python 3.11

Expected Behavior

should work

Actual Behavior

is broken, see scipopt/PySCIPOpt#660

The reason is use of non-public API, see there for more details

Additional Information

See also https://groups.google.com/d/msgid/sage-devel/42199586-647d-4dc0-9b88-9ff5c7ff8737n%40googlegroups.com.

[mkoeppe]

Doesn't the failing code come from Cython?

[dimpase]

Hmm, are you saying that our Cython does not support Python 3.11?

[mkoeppe]

Just saying that if you look for the failing code in the pyscipopt repository, you won't find it

[mkoeppe]

BTW a Cython upgrade is in the making in #35084

[dimpase]

certainly one has to inspect the generated from cython .c file, and see what lines are guilty.

I can reproduce this on macOS 13 with homebrew and python3.11.2 from python.org. Will post details later, awk atm

[dimpase]

The failures are not obviously traceable to scip.pyx, they quite far, hundreds of lines, from any place mentioning scip.pyx. Indeed, it seems the only hope is Cython update here.

Should this be a blocker, or we just deprecate it to experimental?

[mkoeppe]

Let's do the Cython upgrade and see.

[dimpase]

Let's do the Cython upgrade and see.

Are you working on it?

[mkoeppe]

If you have time to work on it now, go for it. I can't get to it before tomorrow or so.

[mkoeppe]

The problem is simply that we are using the PyPI sdist of PySCIPOpt, which contains a scip.c that was prebuilt with an old Cython (/* Generated by Cython 0.29.28 */).

[dimpase]

blyad'! (pardon my French)