error[E0025]: field `a` bound multiple times in the pattern
  --> $DIR/E0025.rs:8:21
   |
LL |     let Foo { a: x, a: y, b: 0 } = x;
   |               ----  ^^^^ multiple uses of `a` in pattern
   |               |
   |               first use of `a`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0025`.