Derive Debug for SyncConnectionWrapper

[tibbe]

This is needed when trying to use tower-sessions with this crate. tower-sessions requires Debug for the provided backend store. In my particular case the store looks like:

type SqlitePool = deadpool::Pool<SyncConnectionWrapper<sqlite::SqliteConnection>>;

#[derive(Clone, Debug)]
pub struct AsyncSqliteStore {
    pool: SqlitePool,
}

The error without this Debug impl is:

`diesel_async::sync_connection_wrapper::SyncConnectionWrapper<diesel::SqliteConnection>` doesn't implement `std::fmt::Debug`
the trait `std::fmt::Debug` is not implemented for `diesel_async::sync_connection_wrapper::SyncConnectionWrapper<diesel::SqliteConnection>`, which is required by `deadpool::managed::Pool<diesel_async::pooled_connection::AsyncDieselConnectionManager<diesel_async::sync_connection_wrapper::SyncConnectionWrapper<diesel::SqliteConnection>>>: std::fmt::Debug`

[tibbe]

The particular trait I need to implement that required Debug is https://docs.rs/tower-sessions/0.13.0/tower_sessions/trait.SessionStore.html.

[tibbe]

The MacOS build failures seem unrelated.

[weiznich]

Thanks for submitting this PR.
Can you explain why this would be actual helpful for your use-case as #[derive(Debug)] only implements Debug if all generic parameters (in this case C) implements Debug on their own. I think all of the possible types for C (especially the SqliteConnection type) do not implement Debug on their own, so this won't actually be used at all.

[tibbe]

It's a first step. I think need to work on e.g. SqliteConnection.

[weiznich]

As I had that discussion already a few times: The connection types do not implement Debug because there is nothing you can reasonably show there. They only hold a few opaque pointers to c objects. We also do not want to store the database URL in their as that could leak confidential information (login credentials, etc).

[tibbe]

Fair enough. I will close this PR then.