error[E0423]: expected function, tuple struct or tuple variant, found struct `X`
  --> $DIR/issue-64792-bad-unicode-ctor.rs:3:14
   |
LL | struct X {}
   | ----------- `X` defined here
LL | 
LL | const Y: X = X("ö");
   | -------------^------
   | |            |
   | |            did you mean `X { /* fields */ }`?
   | |            help: a constant with a similar name exists: `Y`
   | similarly named constant `Y` defined here

error: aborting due to previous error

For more information about this error, try `rustc --explain E0423`.