error: the function has a cognitive complexity of (3/0)
  --> $DIR/cognitive_complexity_attr_used.rs:9:4
   |
LL | fn kaboom() {
   |    ^^^^^^
   |
   = help: you could split it up into multiple smaller functions
   = note: `-D clippy::cognitive-complexity` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::cognitive_complexity)]`

error: aborting due to 1 previous error