Fix E0398: Rust Compiler Error E0398 Explained

Mon, 06 Jul 2026 07:56:04 +0800

1. Symptoms

The Rust compiler emits error E0398 when you attempt to implement an item that does not override anything from a trait definition. This error typically manifests during compilation and prevents the code from building successfully.

When you encounter E0398, you will see output similar to the following:

error[E0398]: `impl_item` is not a method from the trait
 --> src/main.rs:3:5
  |
3 |     fn impl_item(&self) { }
  |     ^^^^^^^^^^^^^^^^^^
  |
  = note: this error function's name doesn't follow the naming convention of its trait

The error message indicates that the compiler has found an impl block containing a method or associated item that does not correspond to any item defined in the target trait. This situation commonly arises when you rename a method in your trait definition but forget to update the corresponding implementation, or when you accidentally add an extra method to an impl block that should only contain trait implementations.

Override on ErrorVault — Developer Error Code Dictionary

Fix E0398: Rust Compiler Error E0398 Explained

1. Symptoms