Open HuangRicky opened 4 years ago
I have run into the same problem. @tkralphs
Result - Problem proven infeasible
No feasible solution found
Enumerated nodes: 0
Total iterations: 0
Time (CPU seconds): 0.00
Time (Wallclock seconds): 0.00
Total time (CPU seconds): 0.00 (Wallclock seconds): 0.00
> /Users/mkoeppe/s/sage/cvxpy/cvxpy/reductions/solvers/conic_solvers/cbc_conif.py(187)solve_via_data()
-> solution = {}
(Pdb) p cbcModel.solutionCount
0
(Pdb) p cbcModel.status
'solution'
The code for https://github.com/coin-or/CyLP/blob/master/cylp/cy/CyCbcModel.pyx#L152 looks rather suspicious.
Looks like there are no tests in https://github.com/coin-or/CyLP/blob/master/cylp/tests/test_MIP.py for infeasible integer models.
I think this should now be fixed in #150, but I've only done minimal testing. Can you check it and let me know? I will try to add some tests, too, but that's a whole can of worms that I was putting off "until I have time." There is at least one test that is failing and can't be easily fixed.
It is difficult to tell whether it's CyLP issue or cvxpy issue but i'm using CyLP with cvxpy. I got these verbose output: (I tried the pypi version as well latest compiled trunk version as of Nov 10, 2019)
However, cvxpy's problem object didn't capture this infeasible, it is still "optimal".
I post this issue here to see if someone happen to understand this Result - Problem proven infeasible message and make sure it's reported correctly to cvxpy (something like standard exit code, etc)
Thank you very much.