Lifetime-extended variable incorrectly reported as 'static

[DaniPopes]

rust-analyzer version: 0.3.2577-standalone

rustc version: rustc 1.91.0-nightly (05f5a58 2025-08-19)

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repository link (if public, optional): N/A

code snippet to reproduce:

fn main() {
    let x = 0usize;
    let _s = match Some(()) {
        Some(()) => &format!("{x}"),
        None => "",
    };
}

_s' type hint is &'static str

[ChayimFriedman2]

That's because we don't implement lifetimes correctly (or rather: we don't implement lifetimes, period).

To be a bit more technical: we create an inference var for the lifetime and then when it's equated it's inferred to be 'static, while we should not be using a var here.

[flodiebold]

Isn't the problem rather that we don't do a least upper bound and (I assume) instead just equate the types (and hence lifetimes)?

[ChayimFriedman2]

This if "fixed", probably by #20664, but it's probably just irrelevant because that PR made us not handle lifetimes.