A super trait has been added to an auto trait.
Erroneous code example:
#![feature(auto_traits)]
auto trait Bound : Copy {} // error!
fn main() {}Since an auto trait is implemented on all existing types, adding a super trait
would filter out a lot of those types. In the current example, almost none of
all the existing types could implement Bound because very few of them have the
Copy trait.
To fix this issue, just remove the super trait:
#![feature(auto_traits)]
auto trait Bound {} // ok!
fn main() {}