`use $crate::{self};` should not be accepted

[theemathas]

tried this code:

macro_rules! foo {
    () => {
        use $crate::{self};
    };
}

foo!();

I expected a compile error of some sort. Instead, it compiles fine.

Based on the error message when I try to import it twice, I'm guessing that it's importing the current crate with the name $crate.

Importing it twice

macro_rules! foo {
    () => {
        use $crate::{self};
    };
}

foo!();
foo!();

fn main() {}

error[E0252]: the name `$crate` is defined multiple times
 --> src/main.rs:3:22
  |
3 |         use $crate::{self};
  |         -------------^^^^--
  |         |            |
  |         |            `$crate` reimported here
  |         |            previous import of the module `$crate` here
  |         help: remove unnecessary import
...
7 | foo!();
  | ------ in this macro invocation
  |
  = note: `$crate` must be defined only once in the type namespace of this module
  = note: this error originates in the macro `foo` (in Nightly builds, run with -Z macro-backtrace for more info)

I am also able to use this import via the name $crate:

Using the import

macro_rules! foo {
    () => {
        use $crate::{self};
        use crate::$crate as lol;
    };
}

foo!();

fn wtf() {
    println!("wtf");
}

fn main() {
    lol::wtf();  // this compiles
}

Surely, this $crate identifier should not be able to be used as an actual name?

See also #146968 for more nonsense with $crate.

Meta

Reproducible on the playground with version 1.92.0-nightly (2025-09-23 975e6c8fec280816d24f)

[mu001999]

@rustbot claim

[petrochenkov]

Duplicate of one of the issues listed in #119776 (comment).
Imports should always end up having a name (#35612 (comment)).

[theemathas]

I found a similar weirdness with extern crate: #149018

[petrochenkov]

Fixed in #146972.