Catch SCIP errors / throw Python errors

[VonAlphaBisZulu]

PySCIPOpt's error management should be improved. There are many situations in which very simple problems resolve in uncaught errors and crash the parent python program.

Here is one simple example: Create an empty model, solve it, call freeReoptSolve, solve again.

from pyscipopt import Model

m = Model()
print('first optimization')
m.optimize()
print('change state')
m.freeReoptSolve()
print('state changed, 2nd optimization')
m.optimize()
print('done')

This goes into a segmentation fault that ends the Python thread. This should rather throw an error in Python with some more explanation on how to avoid it.

Just to be clear: I do not need help with the particular problem mentioned above. I just suggest catching errors and forwarding them to the python error stream.

[VonAlphaBisZulu]

Throwing the error in Python and showing the original error message would (1) help identify the problem (2) allow making use of Python debugging mode

[CGraczyk]

Hi, that does sound like a useful extension of the code! If you have a workaround for this issue or extended the code base on your side, please feel free to create a merge request and we can have a look to integrate this into the master.

Thanks for letting us know.

[VonAlphaBisZulu]

I wish I had, but unfortunately, I never dived deep enough into PySCIPOpt's code. Maybe someone can tag this issue as enhancement.