I'd want to blame Go's compatibility guarantee for this, but I can't because it wouldn't actually stop them from adding a proper solution for this..

Just like the magic comments, it's a sad thing to see appear in this language because it feels like magic incantations one has to know that bend over backwards to not actually extend the language to fit the use case.

Go's full of hacks, and holds no shame over it. Zero-initialized everything, and proceeding to 'defer' instead of RAII, generic builtin types despite lack of generics (until recently), no builtin list type, slices having capacity...

This was Go's design philosophy until Rob Pike left - to do the simple thing simply and not try to be clever about it.

So, like https://doc.rust-lang.org/std/marker/index.html?

The whole Go design philosophy in one sentence, that is what one gets by refusing to adopt modern language practices.

Every language can't be rust.

It's not really a hack. It's a hint to a static analyser, that's all.