error[E0412]: cannot find type `__Origin` in this scope
  --> $DIR/unpin_sneaky.rs:10:16
   |
10 | impl Unpin for __Origin {} //~ ERROR E0412,E0321
   |                ^^^^^^^^ not found in this scope

error[E0321]: cross-crate traits with a default impl, like `Unpin`, can only be implemented for a struct/enum type, not `[type error]`
  --> $DIR/unpin_sneaky.rs:10:1
   |
10 | impl Unpin for __Origin {} //~ ERROR E0412,E0321
   | ^^^^^^^^^^^^^^^^^^^^^^^ can't implement cross-crate trait with a default impl for non-struct/enum type