alt Hacker NewsFuzzing handles the logic verification, but I'd be more worried about the architectural debt of mapping GC patterns to Rust. You often end up with a mess of Arc/Mutex wrappers and cloning just to satisfy the borrow checker, which defeats the purpose of the port.
That will vary depending on how the code is architected to begin with, and the problem domain. Single-ownership patterns can be refactored into Rust ownership, and a good AI model might be able to spot them even when not explicitly marked in the code.
For some problems dealing with complex general graphs, you may even find it best to use a Rust-based general GC solution, especially if it can be based on fast concurrent GC.