error: unreachable pattern
  --> $DIR/unreachable-arm.rs:11:9
   |
LL |         Foo::A(_, 1) => { }
   |         ^^^^^^^^^^^^
   |
note: lint level defined here
  --> $DIR/unreachable-arm.rs:4:9
   |
LL | #![deny(unreachable_patterns)]
   |         ^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error