Conflicting implementation error after updating to 0.16 from 0.15

[DmitriK]

Setup

Versions

• Rust: 1.20.0
• Diesel: 0.16.0
• Database: sqlite
• Operating System Arch Linux

Feature Flags

• diesel: "sqlite"
• diesel_codegen: "sqlite"

Problem Description

My application builds fine when using diesel 0.15.2 and diesel_codegen 0.15.0. After running cargo update, both were updated to 0.16.0. When I try to build, I get the following error:

error: recursion limit reached while expanding the macro `table_body`
  --> src/db.rs:19:5
   |
19 |     infer_schema!("dotenv:DATABASE_URL");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider adding a `#![recursion_limit="128"]` attribute to your crate
   = note: this error originates in a macro outside of the current crate

OK, do what the compiler says, and add #![recursion_limit="128"] to the crate. Build now fails with:

error[E0119]: conflicting implementations of trait `diesel::JoinTo<db::schema::__diesel_infer_schema::infer_presols::presols::table>` for type `db::schema::__diesel_infer_schema::infer_awards::awards::table`:
  --> src/db.rs:19:5
   |
17 |     infer_schema!("dotenv:DATABASE_URL");
   |     ------------------------------------- first implementation here
18 | 
19 |     joinable!(awards -> presols(presol_id));
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `db::schema::__diesel_infer_schema::infer_awards::awards::table`
   |
   = note: this error originates in a macro outside of the current crate

error[E0119]: conflicting implementations of trait `diesel::JoinTo<db::schema::__diesel_infer_schema::infer_awards::awards::table>` for type `db::schema::__diesel_infer_schema::infer_presols::presols::table`:
  --> src/db.rs:19:5
   |
17 |     infer_schema!("dotenv:DATABASE_URL");
   |     ------------------------------------- first implementation here
18 | 
19 |     joinable!(awards -> presols(presol_id));
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `db::schema::__diesel_infer_schema::infer_presols::presols::table`
   |
   = note: this error originates in a macro outside of the current crate

error: aborting due to 2 previous errors

Based on older bugs, I tried to add the 'large-tables' feature to diesel, but it does not fix it. Reverting to 0.15* fixes it. In the meantime, I'll just make do by holding the version back, but it doesn't seem right that an update resulted in build failures.

Steps to reproduce

Module triggering error:

mod schema {
    use diesel::Table;

    infer_schema!("dotenv:DATABASE_URL");

    joinable!(awards -> presols(presol_id));
}

Schema:

$ diesel print-schema
table! {
    awards (id) {
        id -> Integer,
        date -> Nullable<Text>,
        awdDate -> Nullable<Text>,
        awdNbr -> Text,
        awardee -> Text,
        url -> Text,
        presol_id -> Integer,
    }
}

table! {
    presols (id) {
        id -> Integer,
        date -> Nullable<Text>,
        subject -> Text,
        description -> Text,
        naics -> Integer,
        url -> Text,
        solnbr -> Text,
        ignored -> Bool,
    }
}

table! {
    scanned_dates (date) {
        date -> Nullable<Text>,
    }
}

Checklist

• [✓] I have already looked over the issue tracker for similar issues.

[Eijebong]

joinable! calls are now inferred by infer_schema!. Just remove it and it should work :)

[DmitriK]

Removed joinable! line and it works perfectly. Thank you!