error[E0731]: transparent enum needs exactly one variant, but has 2
  --> $DIR/transparent-enum-too-many-variants.rs:4:1
   |
LL | enum Foo {
   | ^^^^^^^^ needs exactly one variant, but has 2
LL |     A(u8), B(u8),
   |     -      - too many variants in `Foo`
   |     |
   |     variant here

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0731`.