- Xcode. A really rough ide that has a hard time at scale, choking on package refreshes, many targets, and more. It has a special entitlement so you can't even binary patch it if you want to fix it!
- Build systems. Cargo is _much_ easier to work with than SPM.
- Macros support, codegen is still largely done outside of the macro system, which should indicate its use.
- Linter / format support. Yeah, it exists, last I checked it's just a good bit worse.
- Performance. There are MANY performance cliffs in Swift; most can be fixed by a sufficiently determined compiler developer, but at this point we've kinda departed talking about the language as-is.
- Type inference time. Swift's bidirectional type inference causes a ton of choking on complex expressions, which is a real problem with its number one use case, SwiftUI.
- An exacerbating factor on the above, imports are all implicitly module-scoped, meaning that changing a single file means recomputing the types for all files in the module. And because SPM and Xcode have such a rough time with multiple targets, that usually means that a single change can lead to recompiling all Swift files.
- Weirdness around classes and structs? I understand that they had to do it for objc compatibility, but I would've found it much cleaner if they'd just from the start had something replacing class, like a fully-sugared `final class Box<T>` that replaces all uses of class.
I agree that for the most part it _could_ be an easier rust, but between including bidirectional type inference without a cut operator and poor tooling I struggle to find where it's actually easier in cases that you can't just use typescript and dodge all the non-typecheck compilation headaches entirely.