Hello.

When playing around with the optimizer I stumbled on similar issues as in #1463 .
On Ctrl-C responding with unknown and the best known intermediate solution unfortunately does not yield any value.
Why can't it be sat instead?
Although not optimal, the model clearly is supposed to satisfy the constraints.

When trying to write intermediate solutions or dumping intermediate models nothing happens.
Should be reproducible with this: foo.txt

Version: 4.13.0