no function or associated item named pool found for struct ConnectionPool in the current scope

[blackghost1987]

I'm setting up a new Rocket project, mostly copy-pasting from and old one, and I keep getting this error when I'm trying to add my Database fairing.

error[E0599]: no function or associated item named `pool` found for struct `ConnectionPool` in the current scope
 --> src\database.rs:7:1
   |
17 | #[database("property_db")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
   | |
   | function or associated item not found in `ConnectionPool<Db, PgConnection>`
   | help: there is an associated function with a similar name: `get_pool`
   |
   = note: this error originates in the attribute macro `database` (in Nightly builds, run with -Z macro-backtrace for more info)

I'm pretty sure this is not a bug and I just messed up something trivial, because I have this exact setup with Diesel and Postgresql in my other project and it's working fine there. Either way, the error message is really not helpful, so I'm pretty stuck.

database.rs:

use diesel::prelude::*;
use diesel::PgConnection;
use rocket_sync_db_pools::database;

pub type Conn = PgConnection;

#[database("property_db")]
pub struct Db(Conn);

main.rs:

#[macro_use]
extern crate rocket;
#[macro_use]
extern crate diesel;

mod database;

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[launch]
fn rocket() -> _ {
    rocket::build()
        .attach(database::Db::fairing())
        .mount("/", routes![index])
}

Rocket.toml:

[global.databases.property_db]
url = "postgresql://...localhost:5432/...."

Cargo.toml:

[dependencies]
diesel = { version = "1.4", default-features = false, features = ["postgres", "chrono", "64-column-tables", "serde_json"] }
diesel_migrations = "1.4.0"
rocket = { version = "=0.5.0-rc.2", features = ["json"] }
rocket_sync_db_pools = { version = "0.1.0-rc.2", features = ["diesel_postgres_pool"] }

Any ideas? What am I missing?

[SergioBenitez]

diesel was updated to version 2 in rc3, which is what you're probably pulling in since you didn't use an = before the rocket_sync_db_pools version. You can either move all deps to RC3 and diesel 2 or use an = before the rocket_sync_db_pools version number in your Cargo.toml.

[blackghost1987]

That was exactly it, just a missing "=" damn 👍 My other project was working because I did not call cargo update on it for a while...
Thanks a lot!

[blackghost1987]

Just for posteriority, I also had to add this line in my Cargo.toml, because even though I pinned rocket_sync_db_pools to rc.2, it still tried to load rc.3 of the codegen

rocket_sync_db_pools_codegen = { version = "=0.1.0-rc.2"}