Confusing error with :: on struct

[comex]

The following code was my incorrect attempt to explicitly specialize a static method:

trait Test {
    fn hello();
}

fn main() {
    struct T;
    impl Test for T {
        fn hello() {}
    }
    T::hello();
}

In fact, apparently the fn is not yet possible to call at all. However, the error output is needlessly confusing with an error!() message and three errors:

!!! (resolving module in lexical scope) module wasn't actually a module!
/tmp/r.rs:10:4: 10:12 error: unresolved name
/tmp/r.rs:10     T::hello();
                 ^~~~~~~~
/tmp/r.rs:10:4: 10:12 error: use of undeclared module `T`
/tmp/r.rs:10     T::hello();
                 ^~~~~~~~
!!! (resolving module in lexical scope) module wasn't actually a module!
/tmp/r.rs:10:4: 10:12 error: unresolved name `T::hello`.
/tmp/r.rs:10     T::hello();

[geoffhill-zz]

The "!!!" lines should be internal debugs, not user printouts. Adding a pull request to fix this, but not sure if any additional behavior here needs to be fixed. Are there existing instances where the Rust compiler warns you if you attempt to use a C++ OOP feature?

[huonw]

Fixed by #11623.