Tuple unpacking and '_' - not being discarded?

[jrfondren]

You're not missing something. It looks like a bug. But I don't see it in 1.4.0: 
    
    
    let (a, _) = (1, 2)
    echo 2
    
    
    Run

This hints about unused `a` and not about any other unused variable. If I echo 
`a` instead I get no hints.