> But it doesn't address all kinds of other logic errors/bugs. It's like closing one door to the barn, but there are six more still wide open.

Could you point at some language features that exist in other languages that Rust doesn't have that help with logic errors? Sum types + exhaustive pattern matching is one of the features that Rust does have that helps a lot to address logic errors. Immutability by default, syntactic salt on using globals, trait bounds, and explicit cloning of `Arc`s are things that also help address or highlight logic bugs. There are some high level bugs that the language doesn't protect you from, but I know of now language that would. Things like path traversal bugs, where passing in `../../secret` let's an attacker access file contents that weren't intended by the developer.

The only feature that immediately comes to mind that Rust doesn't have that could help with correctness is constraining existing types, like specifying that an u8 value is only valid between 1 and 100. People are working on that feature under the name "pattern in types".

IMO, simplicity is the number one feature. The developer should spend their attention on the problem space as much as possible, and on the solution space as little as possible.

There's a complexity cost to adding features, and while each one may make sense on its own, in aggregate they may collectively burden the developer with too much complexity.