tests/ui/map_err.stderr

error: `map_err(|_|...` wildcard pattern discards the original error
  --> tests/ui/map_err.rs:22:32
   |
LL |     println!("{:?}", x.map_err(|_| Errors::Ignored));
   |                                ^^^
   |
   = help: consider storing the original error as a source in the new error, or silence this warning using an ignored identifier (`.map_err(|_foo| ...`)
   = note: `-D clippy::map-err-ignore` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::map_err_ignore)]`

error: aborting due to 1 previous error