I’m not sure why you’re downvoted here. While it’s true I mentioned unsoundness in my comment, when talking about this I do mean it in the senses you are talking about. It’s just that, as you correctly identified in your first reply, the original assertion is that most programs do not compile, and that specific example is the most straightforward way to acknowledge “yes, it is true that there are non-zero programs which compiled in 1.0 that do not compile today.” Soundness issues aren’t the only example, as I alluded to in my other reply done there, just the easiest one to acknowledge that it’s non-zero. But as also repeated above by both myself and burntsushi at least, the team doesn’t take a “well we said we could” approach to breakage; if breakage would be significant, the rust project either does it another way or doesn’t do it. This means that I believe, as you say, that the original assertion isn’t right. Most programs do still work.

I didn’t get to it in my other comment, but I appreciate your work clarifying in this thread previously; I didn’t see I was mentioned until well after you had made some comments. You did explain the gist of what I was getting at. I wish people wouldn’t suddenly start downvoting someone because they believe you’re wrong all of a sudden.