error: approximate value of `f{32, 64}::consts::PI` found
  --> $DIR/proc_macro.rs:9:14
   |
LL |     let _x = 3.14;
   |              ^^^^
   |
   = help: consider using the constant directly
   = note: `#[deny(clippy::approx_constant)]` on by default

error: aborting due to 1 previous error