The Rust Language Server is usable. It works well on valid code, but struggles to deal with invalid states during editing. It can also be painfully slow in large codebases - when working on materialize it was often 3-5x slower than just running cargo check.

I haven't tried the intellij rust plugin or rust-analyzer.

I haven't yet tried the Zig Language Server but it appears to be fairly complete.

I still haven't internalized the full rule-set of rust enough to be able predict whether a design in my head will successfully compile. I don't remember the order in which methods are resolved during autoderefencing, or how module visibility works, or how the type system determines if one impl might overlap another or be an orphan. There are frequent moments where I know what I want the machine to do but struggle to encode it into traits and lifetimes.

On the other hand, we can't type-check zig libraries which contain generics. We can only type-check specific uses of those libraries.

of the unfortunately named release-fast mode which disables all runtime safety checks.