   Compiling my-app v0.1.0 (/home/user/my-app)
warning: unused variable `x`
  --> src/main.rs:15:5
   |
15 |     let x = 42;
   |         ^ help: if you intended to use `x`, consider using a variable name that starts with an underscore: `_x`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: unused import `std::collections::HashMap`
 --> src/lib.rs:1:5
  |
1 | use std::collections::HashMap;
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.33s
