error[E0081]: discriminant value `0` assigned more than once
  --> $DIR/enum-discrim-autosizing.rs:6:1
   |
LL | enum Eu64 {
   | ^^^^^^^^^
LL |
LL |     Au64 = 0,
   |            - `0` assigned here
LL |
LL |     Bu64 = 0x8000_0000_0000_0000
   |            --------------------- `0` (overflowed from `9223372036854775808`) assigned here

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0081`.