error: very complex type used. Consider factoring parts into `type` definitions
  --> $DIR/type_complexity.rs:4:10
   |
LL | fn f2(_: (u8, (u8, (u8, (u8, (u8, (u8, u8))))))) {}
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D clippy::type-complexity` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::type_complexity)]`

error: aborting due to previous error