ExaModelsMOI is ignoring the old nonlinear API

[klamike]

We should probably error out when given a model that uses the old API. But I don't know how to detect this properly at the MOI level.

julia> using JuMP, ExaModels, MadNLP

julia> m = Model()
A JuMP Model
├ solver: none
├ objective_sense: FEASIBILITY_SENSE
├ num_variables: 0
├ num_constraints: 0
└ Names registered in the model: none

julia> @variable m x
x

julia> @objective m Min x^2 + x + 1
x² + x + 1

julia> madnlp(ExaModel(m))
This is MadNLP version v0.8.12, running with umfpack

Number of nonzeros in constraint Jacobian............:        0
Number of nonzeros in Lagrangian Hessian.............:        1

Total number of variables............................:        1
                     variables with only lower bounds:        0
                variables with lower and upper bounds:        0
                     variables with only upper bounds:        0
Total number of equality constraints.................:        0
Total number of inequality constraints...............:        0
        inequality constraints with only lower bounds:        0
   inequality constraints with lower and upper bounds:        0
        inequality constraints with only upper bounds:        0

iter    objective    inf_pr   inf_du inf_compl lg(mu)  ||d||  lg(rg) alpha_du alpha_pr  ls
   0  1.0000000e+00 0.00e+00 1.00e+00 0.00e+00  -1.0 0.00e+00    -  0.00e+00 0.00e+00   0
   1  7.5000000e-01 0.00e+00 0.00e+00 0.00e+00  -1.7 5.00e-01    -  1.00e+00 1.00e+00h  1

Number of Iterations....: 1

                                   (scaled)                 (unscaled)
Objective...............:   7.5000000000000000e-01    7.5000000000000000e-01
Dual infeasibility......:   0.0000000000000000e+00    0.0000000000000000e+00
Constraint violation....:   0.0000000000000000e+00    0.0000000000000000e+00
Complementarity.........:   0.0000000000000000e+00    0.0000000000000000e+00
Overall NLP error.......:   0.0000000000000000e+00    0.0000000000000000e+00

Number of objective function evaluations             = 2
Number of objective gradient evaluations             = 2
Number of constraint evaluations                     = 2
Number of constraint Jacobian evaluations            = 2
Number of Lagrangian Hessian evaluations             = 1
Total wall-clock secs in solver (w/o fun. eval./lin. alg.)  = 14.406
Total wall-clock secs in linear solver                      =  0.027
Total wall-clock secs in NLP function evaluations           =  0.000
Total wall-clock secs                                       = 14.433

EXIT: Optimal Solution Found (tol = 1.0e-08).
"Execution stats: Optimal Solution Found (tol = 1.0e-08)."

julia> mold = Model()
A JuMP Model
├ solver: none
├ objective_sense: FEASIBILITY_SENSE
├ num_variables: 0
├ num_constraints: 0
└ Names registered in the model: none

julia> @variable mold x
x

julia> @NLobjective mold Min x^2 + x + 1

julia> madnlp(ExaModel(mold))
This is MadNLP version v0.8.12, running with umfpack

Number of nonzeros in constraint Jacobian............:        0
Number of nonzeros in Lagrangian Hessian.............:        0

Total number of variables............................:        1
                     variables with only lower bounds:        0
                variables with lower and upper bounds:        0
                     variables with only upper bounds:        0
Total number of equality constraints.................:        0
Total number of inequality constraints...............:        0
        inequality constraints with only lower bounds:        0
   inequality constraints with lower and upper bounds:        0
        inequality constraints with only upper bounds:        0

iter    objective    inf_pr   inf_du inf_compl lg(mu)  ||d||  lg(rg) alpha_du alpha_pr  ls
   0  0.0000000e+00 0.00e+00 0.00e+00 0.00e+00  -1.0 0.00e+00    -  0.00e+00 0.00e+00   0

Number of Iterations....: 0

                                   (scaled)                 (unscaled)
Objective...............:   0.0000000000000000e+00    0.0000000000000000e+00
Dual infeasibility......:   0.0000000000000000e+00    0.0000000000000000e+00
Constraint violation....:   0.0000000000000000e+00    0.0000000000000000e+00
Complementarity.........:   0.0000000000000000e+00    0.0000000000000000e+00
Overall NLP error.......:   0.0000000000000000e+00    0.0000000000000000e+00

Number of objective function evaluations             = 1
Number of objective gradient evaluations             = 1
Number of constraint evaluations                     = 1
Number of constraint Jacobian evaluations            = 1
Number of Lagrangian Hessian evaluations             = 1
Total wall-clock secs in solver (w/o fun. eval./lin. alg.)  =  5.709
Total wall-clock secs in linear solver                      =  0.000
Total wall-clock secs in NLP function evaluations           =  0.000
Total wall-clock secs                                       =  5.709

EXIT: Optimal Solution Found (tol = 1.0e-08).
"Execution stats: Optimal Solution Found (tol = 1.0e-08)."