Update Ipopt ampl path

[odow]

Closes #112

[mlubin]

Does this actually still work? I thought we dropped support for this in one of the recent changes to how the binaries are built.

[odow]

I guess you're right:

julia> using JuMP, AmplNLWriter, Ipopt

julia> model = Model(() -> AmplNLWriter.Optimizer(Ipopt.amplexe_path))
A JuMP Model
Feasibility problem with:
Variables: 0
Model mode: AUTOMATIC
CachingOptimizer state: EMPTY_OPTIMIZER
Solver name: AmplNLWriter

julia> @variable(model, x)
x

julia> @NLobjective(model, Min, x^2)

julia> optimize!(model)
ERROR: Unable to open the solution file. The most likely cause of this
is the solver executable failing unexpectedly. Unfortunately we don't
have any other information about the solution or what went wrong.
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] read_results at /Users/oscar/.julia/packages/AmplNLWriter/cqDNr/src/AmplNLWriter.jl:617 [inlined]
 [3] optimize!(::AmplNLWriter.AmplNLMathProgModel) at /Users/oscar/.julia/packages/AmplNLWriter/cqDNr/src/AmplNLWriter.jl:429
 [4] optimize!(::AmplNLWriter.AmplNLNonlinearModel) at /Users/oscar/.julia/packages/AmplNLWriter/cqDNr/src/AmplNLWriter.jl:824
 [5] optimize!(::AmplNLWriter.Model{Float64}) at /Users/oscar/.julia/packages/AmplNLWriter/cqDNr/src/MOI_wrapper.jl:400
 [6] optimize!(::MathOptInterface.Bridges.LazyBridgeOptimizer{AmplNLWriter.Model{Float64}}) at /Users/oscar/.julia/packages/MathOptInterface/k7UUH/src/Bridges/bridge_optimizer.jl:264
 [7] optimize!(::MathOptInterface.Utilities.CachingOptimizer{MathOptInterface.AbstractOptimizer,MathOptInterface.Utilities.UniversalFallback{MathOptInterface.Utilities.Model{Float64}}}) at /Users/oscar/.julia/packages/MathOptInterface/k7UUH/src/Utilities/cachingoptimizer.jl:215
 [8] optimize!(::Model, ::Nothing; bridge_constraints::Bool, ignore_optimize_hook::Bool, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /Users/oscar/.julia/packages/JuMP/qhoVb/src/optimizer_interface.jl:130
 [9] optimize! at /Users/oscar/.julia/packages/JuMP/qhoVb/src/optimizer_interface.jl:106 [inlined] (repeats 2 times)
 [10] top-level scope at REPL[7]:1

Looks like it can't find binaries:

shell> /Users/oscar/.julia/artifacts/3fd2ae81f25cb51c29182a72a167f5cf0400ced8/bin/ipopt
dyld: Library not loaded: @rpath/libasl.dylib
  Referenced from: /Users/oscar/.julia/artifacts/3fd2ae81f25cb51c29182a72a167f5cf0400ced8/bin/ipopt
  Reason: image not found

[odow]

Ah. I remember what the syntax was:

Ipopt.amplexe() do path
    model = Model(() -> AmplNLWriter.Optimizer(path))
    @variable(model, x)
    @NLobjective(model, Min, x^2)
    optimize!(model)
end

But I think we decided this was too complicated.