error[E0432]: unresolved import `ImportError`
  --> $DIR/issue-5035.rs:15:5
   |
15 | use ImportError; //~ ERROR unresolved import `ImportError` [E0432]
   |     ^^^^^^^^^^^ no `ImportError` in the root

error[E0404]: expected trait, found type alias `K`
  --> $DIR/issue-5035.rs:13:6
   |
13 | impl K for isize {} //~ ERROR expected trait, found type alias `K`
   |      ^
   |      |
   |      did you mean `I`?
   |      type aliases cannot be used for traits

error: cannot continue compilation due to previous error

You've got a few errors: E0404, E0432
If you want more information on an error, try using "rustc --explain E0404"