> The ABI promises in real world C++ implementations make this even worse. There are legitimate use cases that require good performance and some ABI stability

> The ABI promises in real world C++ implementations make this even worse. There are legitimate use cases that require good performance and some ABI stability guarantees. Like various kinds of closed-source client libraries. Rust doesn't have to serve those use cases, of course. But "stable ABI is bad" is a very broad statement. The real problem here is the lack of packaging solutions for systems programming, which are frequently multi-language in some way. And in the case of closed-source use cases, that would look like binary packages. If we had quality dependency management, we would have different options for different use cases and standard libraries could focus on 90% use cases instead of 99.99% ones. Being all things to all users isn't a winning strategy.