Ambiguous glob import of `main` errors even in library crate

[theemathas]

I compiled the following code with rustc --crate-type=lib repro.rs

mod a {
    pub fn main() {}
}
mod b {
    pub fn main() {}
}

use a::*;
use b::*;

I expected the code to compile, but instead I got the following error:

error[E0659]: `main` is ambiguous
  |
  = note: ambiguous because of multiple glob imports of a name in the same module
note: `main` could refer to the function imported here
 --> repro.rs:8:5
  |
8 | use a::*;
  |     ^^^^
  = help: consider adding an explicit import of `main` to disambiguate
note: `main` could also refer to the function imported here
 --> repro.rs:9:5
  |
9 | use b::*;
  |     ^^^^
  = help: consider adding an explicit import of `main` to disambiguate

warning: unused import: `b::*`
 --> repro.rs:9:5
  |
9 | use b::*;
  |     ^^^^
  |
  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default

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

For more information about this error, try `rustc --explain E0659`.

In a library crate, rustc shouldn't be caring whether a function is named main or not.

Renaming both functions from main to foo makes the code compile without errors.

Possibly relevant code:

rust/compiler/rustc_resolve/src/lib.rs

Line 1875 in 88bd39b

self.tcx.sess.time("resolve_main", || self.resolve_main());

Meta

rustc --version --verbose:

rustc 1.93.0-nightly (80d8f292d 2025-11-25)
binary: rustc
commit-hash: 80d8f292d82d735f83417221dd63b0dd2bbb8dd2
commit-date: 2025-11-25
host: aarch64-apple-darwin
release: 1.93.0-nightly
LLVM version: 21.1.5

[theemathas]

Oddly enough, the error doesn't appear when the mains are both consts

mod a {
    pub const main: i32 = 2;
}
mod b {
    pub const main: i32 = 1;
}

use a::*;
use b::*;

[21aslade]

@rustbot claim
Doesn't seem bad