warning: type `Priv` is more private than the item `Leak`
  --> $DIR/struct-field-type.rs:3:5
   |
LL |     pub type Leak = Priv;
   |     ^^^^^^^^^^^^^ type alias `Leak` is reachable at visibility `pub(crate)`
   |
note: but type `Priv` is only usable at visibility `pub(self)`
  --> $DIR/struct-field-type.rs:2:5
   |
LL |     struct Priv;
   |     ^^^^^^^^^^^
   = note: `#[warn(private_interfaces)]` on by default

error: type `Priv` is private
  --> $DIR/struct-field-type.rs:7:5
   |
LL |     field: m::Leak,
   |     ^^^^^ private type

error: aborting due to 1 previous error; 1 warning emitted