MIP start and Heuristic callback


I would like to receive a message about constraint violation when using heuristic callback. When I warm start the model, if there is an infeasibility, I obtain

user MIP start violates constraints constraint_name by value

Instead, in the Heuristic callback, the message is


but there is no additional explanation about violation of constraints.

In the MOI.callback.jl of gurobi.jl (MOI.HeuristicCallback), a solution is created, then the solution is passed to GRBcbsolution and the objective function value is got back and checked with respect to GRB_INFINITY to eventually return


Otherwise, rejected.

Is there a way to hack the code to get some additional information about the infeasibility of the partial solution passed with the heustistic callback?
I want to know if the partial solution is infeasible or if gurobi does not complete the (feasible) partial solution I submitted.

You could ask Gurobi support for more information, but i don’t know of a way to find out why Gurobi rejected the solution.