error[E0263]: lifetime name `'a` declared twice in the same scope
  --> $DIR/E0263.rs:1:16
   |
LL | fn foo<'a, 'b, 'a>(x: &'a str, y: &'b str) {
   |        --      ^^ declared twice
   |        |
   |        previous declaration here

error: aborting due to previous error

For more information about this error, try `rustc --explain E0263`.