It has 1.8 million lines of rust. That compilation time seems close to what I'd expect at that size. If you want something faster you should focus on distributed build caching rather than speeding up the compiler. Also note that crates are effectively equivalent to a single file in c++ as it's the compilation unit. This is similar to compiling 2k files that average 1k loc each in c++. I'm sure it's much worse when you account for macro expansion and generics.