--- /dev/null
+error: `darth` already exists, having another argument having almost the same name makes code comprehension and documentation more difficult
+ --> $DIR/duplicate_underscore_argument.rs:4:23
+ |
+LL | fn join_the_dark_side(darth: i32, _darth: i32) {}
+ | ^^^^^
+ |
+ = note: `-D clippy::duplicate-underscore-argument` implied by `-D warnings`
+
+error: aborting due to previous error
+