[rust-lang/rust] `#[derive(Deserialize)]` makes rustc sugget suggests bizarre and non-working `use crate::_::_serde::de::Error;` instead of `use serde::de::Error;`

### ROOT CAUSE The issue arises because the `#[derive(Deserialize)]` attribute generates code that uses the internal `serde` module (`crate::_serde::de::Error`) instead of the public API (`serde::de::Error`). This is due to the way the `Deserialize` derive macro is implemented, which incorrectly references the internal module. The `custom` method is part of the public `serde::de::Error` trait, but the generated code uses an internal variant, causing the method to be unavailable. ### CODE FIX To resolve this, modify the `Deserialize` derive macro to use the public `serde::de::Error` instead of the internal `_serde::de::Error`. This change ensures that the generated code uses the stable public API, making the `custom` method available. Here's the fix: ```rust // In the generated code, change: use crate::_serde::de::Error; // To: use serde::de::Error; ``` This adjustment ensures that the `custom` method is recognized, resolving the compilation error. Note that this fix requires modifying the `serde` crate's `Deserialize` derive macro implementation.