use super as some_name is invalid

[surma]

I tried this code (playground):

pub mod mod1 {
    pub const thing: bool = true;
    pub mod mod2 {
        use super as my_super;

        pub fn print() {
            println!("{}", my_super::thing);
        } 
    }
}

fn main() {
    mod1::mod2::print();
}

I expected to see this happen: It should compile and run.

Instead, this happened: It fails with

error[E0432]: unresolved import `super`
 --> mytest.rs:4:13
  |
4 |         use super as my_super;
  |             ^^^^^^^^^^^^^^^^^ no `super` in the root

Looking at the relevant part of the reference, it seems the above is at least grammatically correct.

I would love for this to work. However, if this is supposed to not work, a better error message would be great.

Meta

rustc --version --verbose:

rustc 1.44.1 (c7087fe00 2020-06-17)
binary: rustc
commit-hash: c7087fe00d2ba919df1d813c040a5d47e43b0fe7
commit-date: 2020-06-17
host: x86_64-unknown-linux-gnu
release: 1.44.1
LLVM version: 9.0

[petrochenkov]

Duplicate of #35612 #29036 #37156