Incorrect E0308: expected &(dyn ToSql + Sync), found &i32

[erikschul]

When using deadpool_postgres, I encountered incorrect diagnostic for E0308.
The code compiles correctly, but rust-analyzer shows an error.

See details: bikeshedder/deadpool#296 (comment)

rust-analyzer version: 0.3.1799-standalone (af40101 2024-01-07)

rustc version: rustc 1.75.0 (82e1608df 2023-12-21)

Possibly related:

• FP type mismatch on DSTs  #16293
• Various E0308/E0107 errors in rustc code #15332

[erikschul]

One temporary solution is to disable the diagnostic: "rust-analyzer.diagnostics.disabled": ["E0308"]

[lynxlevin]

I am seeing another similar case when using deadpool-redis.
The code below gives expected Option<String>, found String E0308 error, though cargo check does not give any error.

rust-analyzer version: 0.3.2045
rustc version: 1.79.0 (129f3b996 2024-06-10)
editor or extension: VSCode
code snippet to reproduce:

async fn get_from_redis(
    redis_connection: &mut deadpool_redis::Connection,
    key: String,
) -> Option<String> {
    redis_connection
        .get::<String, Option<String>>(key)
        .await
        .unwrap()
}
// deadpool-redis version is "0.15.1"

The signature for the get method is as below, it looks like analyzer is applying the annotation for RV to both K and RV.

pub fn get<'a, K, RV>(&'a mut self, key: K) -> crate::types::RedisFuture<'a, RV>