Perhaps other system programming languages can learn from D language where the DMD, D's reference compiler, compile itself and the entire standard library in less than 5 seconds, with parallelism turned off [1].
[1] Ask HN: Why do you use Rust, when D is available?
[1] Ask HN: Why do you use Rust, when D is available?
https://news.ycombinator.com/item?id=23494490