src/tools/clippy/tests/ui/len_zero_unstable.stderr

error: length comparison to zero
  --> tests/ui/len_zero_unstable.rs:5:5
   |
LL |     vertices.len() == 0
   |     ^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `vertices.is_empty()`
   |
   = note: `-D clippy::len-zero` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::len_zero)]`

error: aborting due to 1 previous error