```
error: cannot find attribute `empty_helper` in this scope
--> $DIR/derive-helper-legacy-limits.rs:17:3
|
LL | #[empty_helper]
| ^^^^^^^^^^^^
|
help: `empty_helper` is an attribute that can be used by the derive macro `Empty`, you might be missing a `derive` attribute
|
LL + #[derive(Empty)]
LL | struct S2;
|
```
Look at proc-macro attributes when encountering unknown attribute
```
error: cannot find attribute `sede` in this scope
--> src/main.rs:18:7
|
18 | #[sede(untagged)]
| ^^^^
|
help: the derive macros `Serialize` and `Deserialize` accept the similarly named `serde` attribute
|
18 | #[serde(untagged)]
| ~~~~~
error: cannot find attribute `serde` in this scope
--> src/main.rs:12:7
|
12 | #[serde(untagged)]
| ^^^^^
|
= note: `serde` is in scope, but it is a crate, not an attribute
help: `serde` is an attribute that can be used by the derive macros `Serialize` and `Deserialize`, you might be missing a `derive` attribute
|
10 | #[derive(Serialize, Deserialize)]
|
```
Don't name variables from external macros in borrow errors.
This came up as part of the expansion of format_args. However, it's a more general problem (and now solution).
I noticed that this does change another test, moving out of fields in derives on packed struct. However, I think this is a better error simply because it used to refer to `other.0` which is an implementation detail which doesn't really make sense.
cc `@m-ou-se`
In 2021 pat was changed to recognize `|` at the top level, with
pat_param added to retain the old behavior. This means
pat is subject to the same cross-edition behavior as expr will be in
2024.
Co-authored-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
There's a subtle interaction between macros with metavar expressions and the
edition-dependent fragment matching behavior. This test illustrates the current
behavior when using macro-generating-macros across crate boundaries with
different editions.
Co-Authored-By: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Co-Authored-By: Eric Holk <eric@theincredibleholk.org>
