shadowed traits from glob imports in the same scope get ignored

[lcnr]

while glob imports from an outer/or nested scope do not

mod glob {
    pub trait Tr {
        fn method(&self) {}
    }
    impl Tr for () {}
}

// use glob::*; // ok
fn main() {
    // use glob::*; // error
    trait Tr {} // no method
    {
        use glob::*; // ok
        ().method();
    }
}

cc @petrochenkov. I want to make sure it's tracked somewhere outside of #144131. Also just really enjoyed learning about this current behavior and wanted to use my test somehow 😁

Originally posted by @lcnr in #144131 (comment)

[yaahc]

I'll make sure this is documented in my updates to the reference.

I set up an alternative version of the example that I find clearer to follow, with some additional working cases that I think help clarify the problem of how shadowing the trait in the glob with the trait specifically removes the shadowed trait from scope only within that scope: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=a61cd824285b47bec094b245fde87078

I think this section I've been working on is related: https://github.com/rust-lang/reference/pull/2055/files#diff-a2f02c849892b164b0ce45c12657594709f859adc8071f77fca70b84fb588767R503

And this pre-existing section: https://github.com/rust-lang/reference/pull/2055/files#diff-a2f02c849892b164b0ce45c12657594709f859adc8071f77fca70b84fb588767R273

[petrochenkov]

We have one test in the test suite checking for the current behavior (tests\ui\shadowed\shadowed-trait-methods.rs), it was added in #31908.
Another relevant issue is #51497.

[petrochenkov]

A fix is implemented in #148943.

[petrochenkov]

#148946 would also fix this.

[petrochenkov]

Analysis of the experiment results - #147992 (comment).