RA reporting ghost lifetime errors

[nappa85]

rust-analyzer version: v0.3.1115

rustc version: 1.62.0 (a8314ef7d 2022-06-27)

relevant settings: none

Randomly RA signals as error a method like:

struct Bar {
    foo: tokio::sync::OnceCell<Foo>,
}

impl Bar {
    pub async fn foo(&self, conn: &DatabaseConnection) -> Result<&Foo, Error> {
        self.foo.get_or_try_init(|| async {
                // Do something with conn to retrieve Foo from DB
            })
            .await
    }
}

Sometimes it gives an error like:

associated function was supposed to return data with lifetime `'1` but it is returning data with lifetime `'2`rustc
mod.rs(87, 15): let's call the lifetime of this reference `'2`
mod.rs(86, 9): let's call the lifetime of this reference `'1`
lifetime may not live long enough
associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`rustc
mod.rs(86, 9): let's call the lifetime of this reference `'1`
mod.rs(87, 15): let's call the lifetime of this reference `'2`

cargo check doesn't complains about it, in facts code builds and run correctly.

I've also tried to satisfy RA requests, like that:

impl Bar {
    pub async fn foo<'a>(&'a self, conn: &DatabaseConnection) -> Result<&'a Foo, Error> {
        self.foo.get_or_try_init(|| async {
                // Do something with conn to retrieve Foo from DB
            })
            .await
    }
}

Sometimes it gives an error like:

associated function was supposed to return data with lifetime `'a` but it is returning data with lifetime `'1`rustc
mod.rs(87, 15): let's call the lifetime of this reference `'1`
mod.rs(85, 30): lifetime `'a` defined here
lifetime may not live long enough
associated function was supposed to return data with lifetime `'1` but it is returning data with lifetime `'a`rustc
mod.rs(85, 30): lifetime `'a` defined here
mod.rs(87, 15): let's call the lifetime of this reference `'1`

Sometimes I save the file and got no errors at all...

[veber-alex]

This looks like Rust bug rust-lang/rust#98890
So it's not an issue in RA.

[flodiebold]

Yes, RA doesn't come up with lifetime errors on its own, so these have to be coming from rustc.

[nappa85]

Thanks