Macro define_sql_function imposes diesel as direct dependency

[Elrendio]

Setup

Versions

• Rust: rustc 1.80.1 (3f5fd8dd4 2024-08-06) binary: rustc commit-hash: 3f5fd8dd41153bc5fdca9427e9e05be2c767ba23 commit-date: 2024-08-06 host: x86_64-unknown-linux-gnu release: 1.80.1 LLVM version: 18.1.7
• Diesel: b170af753c
• Database: N/A
• Operating System N/A

Feature Flags

• diesel: N/A

Problem Description

Use of ::diesel in procedural macro define_sql_function forces to diesel as direct dependency instead of simply in scope, which is bothersome when diesel is re-exported.

What are you trying to accomplish?

Use macro define_sql_function without having diesel as direct dependency

What is the expected output?

Code compiles

What is the actual output?

error[E0433]: failed to resolve: could not find `diesel` in the list of imported crates
  --> /home/elrendio/Stockly/Main/operations/Service/src/supply/Suppliers/src/auto_block/high_at_submission_price_changes.rs:95:4
   |
95 | /             diesel::define_sql_function! {
96 | |                 fn greatest(a: Nullable<Timestamptz>, b: Nullable<Timestamptz>, c: Timestamptz) -> Timestamptz;
97 | |             }
   | |_____________^ could not find `diesel` in the list of imported crates
   |
   = note: this error originates in the macro `diesel::define_sql_function` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider importing this module

Are you seeing any additional errors?

/

Steps to reproduce

1. Create a crate that re-exports diesel, let's call it diesel_helpers
2. Create a second crate with dependency diesel_helpers, let's call it diesel_consumer
3. In crate diesel_consumer, use diesel_helpers::diesel::define_sql_function

Checklist

• [x] I have already looked over the issue tracker and the discussion forum for similar possible closed issues.
• [x] This issue can be reproduced on Rust's stable channel. (Your issue will be closed if this is not the case)
• [x] This issue can be reproduced without requiring a third party crate