error[E0432]: unresolved import `issue_36881_aux`
  --> $DIR/issue-36881.rs:16:9
   |
LL |     use issue_36881_aux::Foo; //~ ERROR unresolved import
   |         ^^^^^^^^^^^^^^^ Maybe a missing `extern crate issue_36881_aux;`?

error: aborting due to previous error

For more information about this error, try `rustc --explain E0432`.