Model.statistics.solutions collects nothing -type solutions

[jardinetsouffleton]

To reproduce:

• Go to the job shop scheduling notebook in SeaPearlZoo.jl
• Run all cells
• After the following cell:

my_heuristic(x::SeaPearl.IntVar; cpmodel=nothing) = minimum(x.domain)
SeaPearl.solve!(model; variableHeuristic=SeaPearl.MinDomainVariableSelection{true}(), valueSelection=SeaPearl.BasicHeuristic(my_heuristic))

Run this:

counter = Dict{String, Int}()
for solution in model.statistics.solutions
    if isnothing(solution)
        if haskey(counter, "null")
            counter["null"] += 1
        else
            counter["null"] = 1
        end
    else
        if haskey(counter, "not_null")
            counter["not_null"] += 1
        else
            counter["not_null"] = 1
        end
    end
end
counter

You should see a very large (~130k) number of nothing in the model.statistics.solutions