Swift can be very painful from this perspective. I just recently had to do surgery on a project because one of my dependencies changed the tools version. The

Swift can be very painful from this perspective. I just recently had to do surgery on a project because one of my dependencies changed the tools version. The back-compat promise is one of the reasons I'm investing in Rust for new projects, even if I find the actual programming much more pleasant in Swift. But I'm a bit less optimistic about Rust now given the recent layoffs at Mozilla.