1 error[E0404]: expected trait, found type alias `Foo`
2 --> $DIR/issue-3907.rs:20:6
4 20 | impl Foo for S { //~ ERROR expected trait, found type alias `Foo`
5 | ^^^ type aliases cannot be used for traits
7 help: possible better candidate is found in another module, you can import it into scope
9 12 | use issue_3907::Foo;
12 error: cannot continue compilation due to previous error