Thats why we run crater against all of crates.io: there are changes that should be allowed that we hold off on because 9f breakage, and fixes we assumed we couldn't land that in reality had no real world impact. As time goes on the confidence a "clean" crater run gives us goes down, due to adoption in closed source environments, but it is still invaluable signal. Depending on the bug, we can keep the current behavior around for prior editions but fix it for future ones.