1 error[E0404]: expected trait, found type alias `Foo`
2 --> $DIR/issue-3907.rs:20:6
4 LL | impl Foo for S { //~ ERROR expected trait, found type alias `Foo`
5 | ^^^ type aliases cannot be used as traits
7 = note: did you mean to use a trait alias?
8 help: possible better candidate is found in another module, you can import it into scope
10 LL | use issue_3907::Foo;
13 error: aborting due to previous error
15 For more information about this error, try `rustc --explain E0404`.