fix build errors against latest scip, fix unit test failures

[alexis779]

My goal was to build PySCIPOpt successfully against the latest version of SCIP.

The reason is that i had a model that was failing in Python, but succeeding with SCIP CLI. So upgrading the version should benefit the community, making available the latest fixes from SCIP.

With the current patch I'm able to access the latest code through the Python binding ...

This PR

• fixes the build errors against latest version of SCIP
• fixes the unit test failures

Would this patch help for upcoming release?

Build SCIP

git clone -b master https://github.com/scipopt/scip
cd scip
mkdir build
cd build
export SCIPOPTDIR=`pwd`
cmake ..
make

Build PySCIPOpt

git clone -b master https://github.com/scipopt/PySCIPOpt
cd PySCIPOpt
python3 -m venv venv
source venv/bin/activate
python -m pip install .

Run tests

pip install -r requirements/test.txt
py.test

=============================== 376 passed, 107 skipped, 11 xfailed, 6 warnings in 46.49s ===============================

[Joao-Dionisio]

Hey @alexis779 ! Thank you for your contribution! I've been slacking off a bit, but the plan is for there to be a new PySCIPOpt release with the last SCIP9 version, and then another one with the SCIP10 version.

The SCIP9 one PR is #1097 and the SCIP10 one is #1009. You can see in #1009 that most of your changes are already there :)