Cargo check fails due to error: 'Only tuple has tuple field'

rust-analyzer version: rust-analyzer version: 0.3.2370-standalone (588948f267 2025-04-06)

rustc version: rustc 1.84.1 (e71f9a9a9 2025-01-27)

editor or extension: VSCode extension version 0.3.2370

code snippet to reproduce:
Cargo.toml

[dependencies]
diesel = { version = "2.2.9", features = ["postgres"] }

lib.rs

pub mod models;
pub mod schema;

schema.rs

diesel::table! {
    posts (id) {
        id -> Int4,
        title -> Varchar,
        body -> Text,
        published -> Bool,
    }
}

models.rs

use diesel::prelude::*;

#[derive(Queryable, Selectable)]
#[diesel(table_name = crate::schema::posts)]
#[diesel(check_for_backend(diesel::pg::Pg))]
pub struct Post {
    pub id: i32,
    pub title: String,
    pub body: String,
    pub published: bool,
}

Remove or comment out one of the fields in the Post struct. RA reports the same error multiple times in the 'Output' pane in VSCode:

2025-04-08T13:22:00.836701386Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>
2025-04-08T13:22:00.836755017Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>
2025-04-08T13:22:00.836777935Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>
2025-04-08T13:22:00.836798345Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>
2025-04-08T13:22:00.839999462Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>
2025-04-08T13:22:00.840047545Z ERROR Only tuple has tuple field: AssocTypeId(Id(121f8))<[?0 := AdtId(StructId(StructId(814e)))<[]>, ?1 := 3<[?0 := !0_405509, ?1 := !0_405510, ?2 := !0_405511]>, ?2 := !0_405508]>

Then whenever I try to save the file, cargo check fails to run and no more new compile time errors/warnings get displayed in the text editor. Other features of RA work such as completions and syntax error detection.

Reproduce the failure with Cargo.toml, lib.rs, schema.rs, and models.rs using the Diesel dependency and the shown Post definition. Start by running cargo check through rust-analyzer with one Post field removed, then trace the repeated “Only tuple has tuple field” errors. Done means cargo check continues to run and new compiler diagnostics appear in the editor without the internal error.