error[E0308]: mismatched types
  --> $DIR/issue-74280.rs:9:5
   |
LL | fn test() -> Test {
   |              ---- expected `_` because of return type
LL |     let y = || -> Test { () };
LL |     7
   |     ^ expected `()`, found integer

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.