-- let.cue --
b: X
let X = int
a: X

-- out/resolve/let --
3[b]:   Scope: 0[<nil>]     Node: 0[]
4[X]:   Scope: 1[*ast.File] Node: 5[let X=int]
6[X]:   Scope: 0[<nil>]     Node: 0[]
7[int]: Scope: 0[<nil>]     Node: 0[]
9[a]:   Scope: 0[<nil>]     Node: 0[]
10[X]:  Scope: 1[*ast.File] Node: 5[let X=int]