Hi all. I have a question about the following MiniZinc model. I am able to give a feasible solution with primal_feasibility_report but nothing is found by the solver. I’m aware of the silliness of the presented model, this is a minimal example of this behavior extracted from a larger model. Thanks!

Thank you for helping check @blegat. For reference, I’m on JuMP v1.22.2 and MiniZinc v0.3.9. The below code is as close as possible to what is going on in my actual use case, I show the example and the result from solution_summary below.

julia> solution_summary(jumpmod)
* Solver : MiniZinc
* Status
Result count : 0
Termination status : OTHER_ERROR
Message from the solver:
"=====ERROR=====
Warning: included file "count.mzn" overrides a global constraint file from the standard library. This is deprecated. For a solver-specific redefinition of a global constraint, override "fzn_<global>.mzn" instead.
/workspace/srcdir/chuffed/chuffed/core/engine.cpp:419: Not yet supported
"
* Candidate solution (result #1)
Primal status : NO_SOLUTION
Dual status : NO_SOLUTION
* Work counters
Solve time (sec) : 4.46848e-01

/workspace/srcdir/chuffed/chuffed/core/engine.cpp:419: Not yet supported

I can reproduce, but I assume this is a bug in Chuffed where you have a degenerate solution with x = 1 but you are asking for multiple solutions? There does’t seem to be any issue in MiniZinc.jl

Thanks. I was curious why it was giving that error and not able to return the single feasible solution despite being degenerate. But it seems like it worked for @blegat based on his previous response?