1error[E0433]: failed to resolve: use of undeclared type `HashMap`
2  --> $DIR/issue-31997-1.rs:20:19
3   |
4LL |     let mut map = HashMap::new();
5   |                   ^^^^^^^ not found in this scope
6   |
7help: consider importing this struct
8   |
9LL | use std::collections::HashMap;
10   |
11
12error: aborting due to previous error
13
14For more information about this error, try `rustc --explain E0433`.
15