rust-foundation-community-grant
rust-foundation-community-grant copied to clipboard
weiznich
Rust Foundation Project Grant 2022
This repository is used to track information about my Rust Foundation Project Grant to improve error messages emitted by rustc for trait heavy crates. As part of this work I will focus on the following points:
- Collect and categorise various examples of non-optimal error messages from the rust ecosystem. This includes error messages generated by crates like diesel, axum or nalgebra which relay heavily on complex trait bounds
- Experiment with example cases to see which error messages could be improved by
the usage of
#[rustc_on_unimplemented] - Implement RFC-2397
- Experiment with example cases to see which error messages could be improved by
the usage of
#[do_not_recommend]
Call for participation
Please submit examples of bad error messages in the context of trait heavy crates as issue or PR (with minimal example) to this repository.
Test cases
| crate | test case | error type |
|---|---|---|
| uom | type_mismatch.rs | type mismatch |
| typed_builder | mismatch.rs | type mismatch + missing free standing function |
| easy_ml | recursion.rs | type recursion |
| diesel | bad_insertable_field.rs | trait not implemented + misleading wildcard impl |
| diesel | bad_sql_query.rs | trait not implemented |
| diesel | invalid_query.rs | traits not implemented + "duplicated errors" |
| diesel | queryable_order_mismatch.rs | trait not implemented with large types |
| chumsky | json.rs | associated type mismatch |
| bevy | system_mismatch.rs | trait not implemented + HRTB error |
| axum | argument_not_extractor.rs | debug_handler |
| axum | extract_self_mut.rs | debug_handler |
| axum | extract_self_ref.rs | debug_handler |
| axum | generics.rs | debug_handler |
| axum | invalid_attrs.rs | debug_handler |
| axum | missing_deserialize.rs | trait not implemented |
| axum | multiple_body_extractors.rs | debug_handler |
| axum | multiple_paths.rs | debug_handler |
| axum | not_a_function.rs | debug_handler |
| axum | not_async.rs | debug_handler |
| axum | not_send.rs | debug_handler |
| axum | request_not_last.rs | debug_handler |
| axum | too_many_extractors.rs | debug_handler |
| axum | wrong_return_type.rs | debug_handler |
| entrait | missing_impl_deep.rs | trait not implemented |
uom
type_mismatch.rs <a name="uom_type_mismatch>
Versions:
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | type_mismatch.rs | type_mismatch.stderr |
typed_builder
Typed builder generates hidden types/deprecating messages to improve its error messages
mismatch.rs
Versions:
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | mismatch.rs | mismatch.stderr |
entrait
missing_impl_deep.rs
Versions:
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | missing_impl_deep.rs | missing_impl_deep.stderr |
easy_ml
recursion.rs
Versions:
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | recursion.rs | recursion.stderr |
diesel
bad_insertable_field.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | bad_insertable_field.rs | bad_insertable_field.stderr | |
| 2 | bad_insertable_field.rs | bad_insertable_field.stderr | https://github.com/diesel-rs/diesel/pull/3228 improves the spans for certain trait bounds so that compiler errors point to the corresponding struct fields instead of the derive |
bad_sql_query.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | bad_sql_query.rs | bad_sql_query.stderr | |
| 2 | bad_sql_query.rs | bad_sql_query.stderr | Add a #[rustc_on_unimplemented] on the corresponding trait. https://github.com/diesel-rs/diesel/commit/958391a3e793e409d0a925e0cc2317726c2d84b2 |
invalid_query.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | invalid_query.rs | invalid_query.stderr | |
| 2 | invalid_query.rs | invalid_query.stderr | Add a #[rustc_on_unimplemented] on the corresponding trait. https://github.com/diesel-rs/diesel/commit/958391a3e793e409d0a925e0cc2317726c2d84b2 |
queryable_order_mismatch.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | queryable_order_mismatch.rs | queryable_order_mismatch.stderr |
chumsky
json.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | json.rs | json.stderr |
bevy
system_mismatch.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | system_mismatch.rs | system_mismatch.stderr | |
| 2 | system_mismatch.rs | system_mismatch.stderr | https://github.com/bevyengine/bevy/pull/5786, which introduces #[rustc_on_unimplemented] attributes in multiple locations |
axum
axum provides a #[debug_handler] attribute which emits better error messages is some cases
argument_not_extractor.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | argument_not_extractor.rs | argument_not_extractor.stderr | |
| 2 | argument_not_extractor.rs | argument_not_extractor.stderr | Fixes to the error spans of #[debug_handler] |
| 3 | argument_not_extractor.rs | argument_not_extractor.stderr | Point to #[debug_handler] |
extract_self_ref
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | extract_self_ref.rs | extract_self_ref.stderr |
extract_self_mut
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | extract_self_mut.rs | extract_self_mut.stderr |
generics
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | generics.rs | generics.stderr |
invalid_attrs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | invalid_attrs.rs | invalid_attrs.stderr |
missing_deserialize.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | missing_deserialize.rs | missing_deserialize.stderr | |
| 2 | missing_deserialize.rs | missing_deserialize.stderr | Point to #[debug_handler] |
multiple_body_extractors
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | multiple_body_extractors.rs | multiple_body_extractors.stderr | |
| 2 | multiple_body_extractors.rs | multiple_body_extractors.stderr | Fixes to the error spans of #[debug_handler] |
| 3 | multiple_body_extractors.rs | multiple_body_extractors.stderr | Point to #[debug_handler] |
multiple_paths
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | multiple_paths.rs | multiple_paths.stderr |
not_a_function
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | not_a_function.rs | not_a_function.stderr |
not_async
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | not_async.rs | not_async.stderr |
not_send
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | not_send.rs | not_send.stderr |
request_not_last
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | request_not_last.rs | request_not_last.stderr | |
| 2 | request_not_last.rs | request_not_last.stderr | Fixes to the error spans of #[debug_handler] |
| 3 | request_not_last.rs | request_not_last.stderr | Point out as part of the error message, that Request always needs to be the last handler argument |
too_many_extractors
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | too_many_extractors.rs | too_many_extractors.stderr |
wrong_return_type.rs
| version | link (code) | link (error message) | change since last version |
|---|---|---|---|
| 1 | wrong_return_type.rs | wrong_return_type.stderr |
weiznich