> Go stands by its compatibility promise—the old way will continue to work in perpetuity ...

It is so weird that they still claim this after they have made the the semantic change for 3-clause for-loop in Go 1.22.

When a Go module is upgraded from 1.21- to 1.22+, there are some potential breaking cases which are hard to detect in time. https://go101.org/blog/2024-03-01-for-loop-semantic-changes-...

Go toolchain 1.22 broke compatibility for sure. Even the core team admit it. https://go101.org/bugs/go-build-directive-not-work.html