> Javac itself is absolutely on the same order of magnitude speed as Go per loc

Not really when it has to run on a cold JVM. And before it warms up, it’s already done.

Then you are in territory of keeping the compiler process between the runs, but that is a memory hog and also not always realiable (gradle often decides to run a fresh daemon for whatever reason).

So theoretically, in lab conditions yes, in practice no.

> while rust is significantly slower

Everybody repeats that but there is surprisingly little evidence in form of benchmarks. I can see rustic compiles over 50k Loc per second on average on my M2, which is roughly the same order of magnitude as Java. And checking without building is faster.