> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sifr.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# SIFR-RUST-SLOT-0004: A method-slot bridge bound is incomplete or misplaced.

> A method-slot bridge bound is incomplete or misplaced.

`SIFR-RUST-SLOT-0004` belongs to the **Rust method slots** diagnostic family. It means: a method-slot bridge bound is incomplete or misplaced.

## Why It Happens

A compiler-emitted method-slot table, context, signature, or call-scoped handler contract was violated.

<Info>
  Use `sifr --explain SIFR-RUST-SLOT-0004` locally to see the renderer's exact message template and any machine-applicable suggestions for the compiler version you are running.
</Info>

## Details

| Field                  | Value                                                                                                          |
| ---------------------- | -------------------------------------------------------------------------------------------------------------- |
| Code                   | `SIFR-RUST-SLOT-0004`                                                                                          |
| Family                 | `RUST-SLOT`                                                                                                    |
| Severity               | Error                                                                                                          |
| Stability              | stable                                                                                                         |
| Owner                  | `sifr_lowering::rust_interop_structural`                                                                       |
| Representative fixture | `crates/sifr_lowering/src/lower/rust_interop_structural_tests.rs::structural_method_slots_require_one_context` |

See the [Error Codes index](/diagnostics/error-codes) for the complete catalog.