Is making the rust compiler slow a billion dollar mistake?

4 breatheoften 3 7/13/2025, 7:10:33 PM
Just wondering if other folks feel growing dissatisfaction with the fact that the current leading modern system programming language does not include fast compilation as one of its fundamental design goals.

To me -- this seems like an obvious candidate for a future 'billion dollar' mistake retrospective essay.

How and why is it that 'support fast compilation' isn't a necessary pre-condition for any modern language hoping to achieve serious usage?

With rust in particular -- it seems like a whole lot of the slow compilation behaviors are not fundamental to any of the most important aspects of the language ...

Is there anyone out there who has tried to fork the rust ecosystem in a way which deliberately breaks compatibility in order to chart the simplest path to a fast, scaleable compilation strategy for the language and ecosystem?

I have a feeling that such an effort -- rust with some misfeatures removed, and with the package system simplified in order to speed up compilation would actually take off and be able to replace the current ecosystem relatively quickly ...

Comments (3)

bjourne · 11m ago
I believe the Rust compiler does whole program analysis or, at least, something very similar in spirit. Hence, unless you completely change how the language works it can't be as fast as a simpler compiler. You can work around it by having a daemon that incrementally compiles only changed parts, but then you need to have that daemon running and it's never as smooth as one command that compiles quickly. In other words, yes, I think you are right. Slow compile times reduce adoption.
MeetingsBrowser · 1h ago
Perfect is the enemy of good, and Rust's compile times are good enough.

When choosing between languages, compile times should be a tie-breaker at most. If Rust had focused on super fast compilation from the start, it probably would have slowed developing the features that actually made it successful.

Its like a startup that spends forever building the perfect scalable backend instead of just solving customer problems. The hacky solution usually wins.

> Is there anyone out there who has tried to fork the rust ecosystem ... I have a feeling that such an effort ... would actually take off and be able to replace the current ecosystem relatively quickly

Forking the entire Rust ecosystem seems pretty unlikely to work, but everything's open source so anyone can give it a shot.

dapperdrake · 58m ago
Is a breaking change really needed? Can there be ABI compatibility and just less (slow) optimization?