error: usage of `process::exit`
  --> tests/ui/exit1.rs:5:9
   |
LL |         std::process::exit(4);
   |         ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D clippy::exit` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::exit)]`

error: aborting due to 1 previous error