Steve is too modest about the tests by the way. Lots of the conformance testing for Rust's compiler happens automatically. Herb mentions Perennial <a href="https://www.peren.com/" rel="nofollow">https://www.peren.com/</a> and Plum Hall <a href="https://plumhall.com/" rel="nofollow">https://plumhall.com/</a> for C++ and Steve says "I'm not saying that functions as a conformance test suite" when it comes to Rust's own compiler tests. But, while the Rust project itself does not perform conformance testing, Ferrous Systems does and so yeah, analogous conformance test suites exist and are run automatically.<p>So when Herb says "And in Rust's case, that's going to need to be built out" if the interview was taking place five years ago that's an important point. But it wasn't five years ago, it was only a few weeks ago.