cannot find type EpisodeMapping in this scope

[lucasholder]

Something weird happened today. After a clean build, my diesel-derive-enum generated EpisodeMapping suddenly stopped working and I can't figure out why.

table! {
    use diesel::sql_types::*;
    use crate::db::enums::episode::*;

    /// Representation of the `heroes` table.
    ///
    /// (Automatically generated by Diesel.)
    heroes (id) {
        /// The `id` column of the `heroes` table.
        ///
        /// Its SQL type is `Int4`.
        ///
        /// (Automatically generated by Diesel.)
        id -> Int4,
        /// The `name` column of the `heroes` table.
        ///
        /// Its SQL type is `Varchar`.
        ///
        /// (Automatically generated by Diesel.)
        name -> Varchar,
        /// The `appears_in` column of the `heroes` table.
        ///
        /// Its SQL type is `Array<EpisodeMapping>`.
        ///
        /// (Automatically generated by Diesel.)
        appears_in -> Array<EpisodeMapping>,
        /// The `home_planet` column of the `heroes` table.
        ///
        /// Its SQL type is `Varchar`.
        ///
        /// (Automatically generated by Diesel.)
        home_planet -> Varchar,
    }
}

error[E0412]: cannot find type `EpisodeMapping` in this scope
   --> src/db/schema.rs:335:29
    |
335 |         appears_in -> Array<EpisodeMapping>,
    |                             ^^^^^^^^^^^^^^ not found in this scope
    |
    = note: possible candidate is found in another module, you can import it into scope:
            crate::db::enums::episode::db_enum_impl_Episode::EpisodeMapping

error: aborting due to previous error

#[derive(Debug, PartialEq, DbEnum, Clone, GraphQLEnum)]
#[PgType = "episode_enum"]
pub enum Episode {
    NewHope,
    Empire,
    Jedi,
}

For some reason the compiler is finding crate::db::enums::episode::db_enum_impl_Episode::EpisodeMapping but not crate::db::enums::episode::EpisodeMapping. I'm not sure what happened, I don't think I touched those modules at all, I just did a clean build. Any idea why this is happening?

[lucasholder]

This fixed the problem:

        /// (Automatically generated by Diesel.)
        appears_in -> Array<crate::db::enums::episode::EpisodeMapping>,

I noticed I have a #![feature(proc_macro_hygiene, decl_macro)] in main.rs file, maybe related? But it's been there forever, wWeird that this error seemed to appear suddenly.

[adwhit]

Curious. I never really got my head around the proc macro hygine. This crate has apparently exposed breakages in proc macros before (e.g. rust-lang/rust#54783) so am inclined to blame rustc here. But would be interested to know the reasons.

[adwhit]

Am assuming this is no longer an issue