`unused_assignments` false positive on diverging path

[oxalica]

Code

#[deny(unused_assignments)]
fn main() {
    let mut x = 1;
    catch(|| {
        x = 2; // <-
        panic!();
    });
    dbg!(x);
}

fn catch<F: FnOnce()>(f: F) {
    if let Ok(true) = std::fs::exists("may_or_may_not_call_f") {
        _ = std::panic::catch_unwind(std::panic::AssertUnwindSafe(f));
    }
}

Current output

error: value assigned to `x` is never read
 --> src/main.rs:5:9
  |
5 |         x = 2; // <-
  |         ^^^^^
  |
  = help: maybe it is overwritten before being read?
note: the lint level is defined here
 --> src/main.rs:1:8
  |
1 | #[deny(unused_assignments)]
  |        ^^^^^^^^^^^^^^^^^^

Desired output

<no error or warning>

Rationale and extra context

This issue only exists if there is a panic!() inside the closure, otherwise no warning is emitted.
The initial value and the assigned value are all useful depending on if catch calls the closure. Neither of them should be considered "unused".

Other cases

Rust Version

1.95.0-nightly (2026-02-02 f60a0f1bcc5a2a6dd8eb)
(reproduced on playground nightly)

Anything else?

playground link

The false positive only exists since 1.92.0 and the same code does not warn on 1.91.0.

[eggyal]

Almost certainly another from #142390

@rustbot label +regression-from-stable-to-stable +L-unused_assignments
@rustbot claim