error: item does not constrain `Bug::{opaque#0}`
  --> $DIR/issue-53092-2.rs:7:7
   |
LL | const CONST_BUG: Bug<u8, ()> = unsafe { std::mem::transmute(|_: u8| ()) };
   |       ^^^^^^^^^
   |
   = note: consider removing `#[define_opaque]` or adding an empty `#[define_opaque()]`
note: this opaque type is supposed to be constrained
  --> $DIR/issue-53092-2.rs:4:18
   |
LL | type Bug<T, U> = impl Fn(T) -> U + Copy;
   |                  ^^^^^^^^^^^^^^^^^^^^^^

error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
  --> $DIR/issue-53092-2.rs:7:41
   |
LL | const CONST_BUG: Bug<u8, ()> = unsafe { std::mem::transmute(|_: u8| ()) };
   |                                         ^^^^^^^^^^^^^^^^^^^
   |
   = note: source type: `{closure@$DIR/issue-53092-2.rs:7:61: 7:68}` (0 bits)
   = note: target type: `{type error}` (the type has an unknown layout)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0512`.