Panic recovery and panics can be disabled, and often are. Libraries are not supposed to rely on their existence. Thus these are not a form of exceptions ; they

Panic recovery and panics can be disabled, and often are. Libraries are not supposed to rely on their existence. Thus these are not a form of exceptions ; they can't be used as such. Their purpose is to recover from panics when embedding Rust in code written in other languages, where you don't want the panic to try and cross the ffi boundary (or to stop applications that should never crash from crashing at the toplevel, or for better reporting before a crash). Many FFI-based applications turn panics into aborts anyway. Firefox does. The unwind-recovery functionality in Rust is just enough to get you these useful features if you need them (zero cost if you don't; turn them into aborts), without needing a full on exception system. The reason Rust avoids an exception system isn't the cost of unwinding, it's because it considers exceptions to be an inferior pattern compared to return value based / monadic error handling. Rust doesn't have a mailing list anymore. I haven't seen much annoyance with panic recovery. There used to be some with panics in general because in the past they couldn't be turned off or recovered from without a new thread, but this has been addressed for ages with panic=abort and recovery. What the hell are you talking about?