How to get HSL up and running with Ipopt

Hi @heiwie!
I think that you use the dummy HSL_jll.jl in your environment (v2.0.0).
You can check if you have the correct HSL_jll.jl with the Julia interface HSL.jl and the package manager.

using HSL
bool = LIBHSL_isfunctional()
(@v1.10) pkg> status HSL_jll
Status `~/.julia/environments/v1.10/Project.toml`
  [017b0a0e] HSL_jll v2023.11.7+0 `~/Applications/libHSL//HSL_jll.jl-2023.11.7`

If you have the version 2.0.0, you need install the complete HSL_jll.jl with:

pkg> dev path/to/HSL_jll