This is a good subject to discuss, but the article doesn't suggest much in the way of specifics. What kinds of libraries (or library refinement) are most wanti

This is a good subject to discuss, but the article doesn't suggest much in the way of specifics. What kinds of libraries (or library refinement) are most wanting? I agree that there's a general green-ness to the current offerings, but it isn't clear where a motivated individual might best spend their energy. In addition to speed and lifetime visualization, another big thing I'd like to see from rustc/RLS is better-localized error messaging. I have a frequent experience where an error in one place will suppress (or cause!) a completely unrelated error somewhere else, even when those bits of code don't interact at all. For example, one function that returns the wrong type may suppress the fact that a different function, in a totally different file, has a similar problem. This makes it very hard to squash errors in a methodical way. It starts to feel like whack-a-mole; traditional boundaries like function signatures don't seem to apply to compiler errors.