error[E0277]: `Rc<u32>` cannot be sent between threads safely
  --> $DIR/cross-crate.rs:14:17
   |
LL |     use_alias::<Rc<u32>>();
   |                 ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
   |
   = help: the trait `Send` is not implemented for `Rc<u32>`
   = note: required because of the requirements on the impl of `SendSync` for `Rc<u32>`
note: required by a bound in `use_alias`
  --> $DIR/cross-crate.rs:10:17
   |
LL | fn use_alias<T: SendSync>() {}
   |                 ^^^^^^^^ required by this bound in `use_alias`

error[E0277]: `Rc<u32>` cannot be shared between threads safely
  --> $DIR/cross-crate.rs:14:17
   |
LL |     use_alias::<Rc<u32>>();
   |                 ^^^^^^^ `Rc<u32>` cannot be shared between threads safely
   |
   = help: the trait `Sync` is not implemented for `Rc<u32>`
   = note: required because of the requirements on the impl of `SendSync` for `Rc<u32>`
note: required by a bound in `use_alias`
  --> $DIR/cross-crate.rs:10:17
   |
LL | fn use_alias<T: SendSync>() {}
   |                 ^^^^^^^^ required by this bound in `use_alias`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.