[MaulingMonkey]

Perhaps to implement https://doc.rust-lang.org/std/panic/fn.catch_unwind.html

But also just to display traces on asserts/panics, even if not "unwound" per se.

[steveklabnik]

By default, rust's panics _do_ unwind the stack. However, you can also set a flag to compile them as an abort instead. Stack traces are still useful in that case.