[namjh]

Big kudos to Rust compiler devs about their sophisticated type system and its kind (and highly intelligent) help messages. A little concern is that AFAIK its complexity in type systems and other static analysis things require deep domain knowledge, so in a far, far future there may be a lack of "core" engineers comparing to a demand much increased at that point. This kind of change looks like already requiring deep understanding of both Rust's type system and internal compiler structure to implement.