How Rust is tested
I love the concept of the "crater run" (or I guess now "cargo bomb"?), where the entire crate (i.e. "package") ecosystem is compiled, as a test for speculative compiler changes.<p>It's one of the huge benefits of being both a statically-typed compiled language and offering a modern package system. A lot of languages have the types & compiling but no standard package ecosystem (Haskell, Go, Java), or the package ecosystem but not the compiling (Ruby+Gems, JS+npm, etc). Rust is the only language I can think of that has both, although I'm sure there are others. I'm not sure if there's tooling for compiler writers in other languages to compile them all, though.<p>And this feature will only get more and more powerful as the ecosystem grows. I think it's a seriously important tool to keep the rust language feeling stable.