Rust also has a saner module system that makes incremental builds much quicker. They're still pretty slow, but not as agonizingly slow as a clean build.

Rust is only fast compared to C++ (and then only sometimes). Literally every other language is significantly faster to compile. I'm hoping this can change though. Rust with fast compile times and a more complete library ecosystem (and ideally better IDE support) would be an incredibly productive language.

Scala is slower to compile than C++ in large scale enterprise development. (The exception that proves the rule?)

Ah, I forgot about Scala. Someone below mentioned Haskell too (which I haven't used). Still, calling Rust fast seems wrong to me!

Compared with C++, Scala projects are not slow to compile when you use Gradle multi-project builds (with granular sub-projects) and Gradle build caching.

Not as agonizingly slow, but still agonizingly slow.

While I do appreciate build speed improvements, saying that it's better than it was isn't a super high bar in terms of user experience.

I love Rust, I really do, but it's still incredibly slow. I'm excited for any progress it makes on this front.

I think the most promising thing on this front is Cranelift (https://github.com/CraneStation/cranelift). The idea is that, when cranelift is ready, we might use it for debug builds (but still use LLVM for release builds).