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by Aurornis 2 hours ago
> I could also see it slipping into obscurity as LLMs get faster and compile times become a more and more obvious bottleneck on iteration speeds.

I’ve worked on some very large Rust projects. The incremental compile times are nowhere near the same order of magnitude of a bottleneck as an LLM turn.

3 comments

I use LLMs and rust and compile times are absolutely a significant area of degradation. I love rust, I think it's the best language for LLMs, but the biggest win Rust could get for agentic development is to speed up the compiler.
How long does a compile take? Because this was the biggest issue for me. I dont really like Python but the ability to make some changes then run it instantly is wild for me.
You probably already know this, but I figure it bears repeating: most people should be running `cargo check` during development, not `cargo build`. The latter is only necessary when you actually need the built binary; the former is sufficient for type- and borrow-checking.

(On my local machine, `cargo check` is roughly 2x faster than `cargo build`. It's still slower than hot-reloaded Python, but it's rarely my development bottleneck.)

A non starter for anything related to graphics or UI development, which is kind of most Rust stuff are CLIs or TUIs, like being back on curses heyday, Turbo Vision and Clipper.
Is it? An immense amount of the world’s graphical software is written for native graphical targets like SwiftUI, where the iteration cycle is similarly bound to build times. It’s certainly painful, but I don’t think it’s a non-starter.
Various Rust UI projects have been working towards hot-reloadable capabilities, based on the work from the Dioxus team.

IME it's just not really that big of a deal at this point. YMMV, etc.

Initial compilation and incremental compilation are very different.

Large Rust projects are broken up into modules. If you change one module you don’t have recompile the whole project.

Remember we’re talking about compensation time versus LLM turns in this thread. Even a 10 second incremental compile is orders of magnitude faster than an LLM turn.

I don't doubt this is true for many projects currently (though it's not for a bevy project I'm working on).

Have you tried Cerebras, Groq, Taalas, et al? It was a paradigm shift for me.

I have, but even with the high token generation speed, incremental Rust compile times were not a bottleneck.

I was disagreeing with the concept that incremental compile times could be a bottleneck. LLMs are even better at doing large swaths of work at once and having it compile first or second try than a human.

Oh are you saying the human remains the bottleneck?