HagerZhangLineSearch: Reached unreachable point in update method.

[4321ba]

I'm using Steepest descent with More-Thuente line search successfully. I decided to try Hager-Zhang, but it crashed with the following message:

2024-11-25T16:32:46.741706Z DEBUG mp3_to_nbs::observer: time: 0.030867625 | gradient_count: 435 | cost_count: 435 | best_cost: 0.0000019191543 | cost: 0.0000019191543 | iter: 69
2024-11-25T16:32:46.770215Z DEBUG mp3_to_nbs::observer: time: 0.028495213 | gradient_count: 441 | cost_count: 441 | best_cost: 0.0000019191539 | cost: 0.0000019191539 | iter: 70
2024-11-25T16:32:46.798639Z DEBUG mp3_to_nbs::observer: time: 0.028410949 | gradient_count: 447 | cost_count: 447 | best_cost: 0.0000019191523 | cost: 0.0000019191523 | iter: 71
2024-11-25T16:32:46.827058Z DEBUG mp3_to_nbs::observer: time: 0.028405967 | gradient_count: 453 | cost_count: 453 | best_cost: 0.0000019191511 | cost: 0.0000019191511 | iter: 72
thread 'main' panicked at src/optimize.rs:145:73:
called `Result::unwrap()` on an `Err` value: Potential bug: "`HagerZhangLineSearch`: Reached unreachable point in `update` method.". This is potentially a bug. Please file a report on https://github.com/argmin-rs/argmin/issues
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

The code I'm using is roughly this, but I'm trying different parameters. Tell me if you need more info, I'm glad to be using this library :D!