`<!` inside nested `let` inside `go` block erroneously yields "<! not used inside go block" error

Actually, my code is a bit more complicated:

You cannot user `for` inside a go block

The `for` cannot appear anywhere inside a `go`? Or the `for` cannot contain inside it any async calls; i.e., is it ok for `for` to appear somewhere in the let binding as a sibling to a call to <!?

You can't use `<!` inside a `for` inside a `go` block, code like this OTOH should be valud:

Ahh, perfect! Thx!