> Rust was started in 2010, and Elm in 2012.

That doesn’t preclude learning from younger langages in any way.

The trend of providing really helpful and valuable error messages (especially compilation) really started with Evan’s “compilers as assistants” and “compiler errors for humans” from 2015, although there had been forays into improvements to e.g. error localisation from clang.

And Rust’s improvements absolutely come from there, as acknowledged by Jonathan Turner’s 2016 “shape of errors to come”: https://blog.rust-lang.org/2016/08/10/Shape-of-errors-to-com... as well as his “new error format” proposal / rfc which eventually lead to the change: https://github.com/jonathandturner/rust_proposals/blob/maste...