> Crater is a tool for compiling and running tests for every crate on crates.io (and a few on GitHub). It is mainly used for checking the extent of breakage when implementing potentially breaking changes and ensuring lack of breakage by running beta vs stable compiler versions.

https://rustc-dev-guide.rust-lang.org/tests/crater.html

https://github.com/rust-lang/crater

https://crater.rust-lang.org/

Even then such a bug as GHC's can conceivably not be detected.