> ## 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-PYZC-0001: An advanced-data ownership, buffer layout, or hidden-copy declaration is invalid.

> An advanced-data ownership, buffer layout, or hidden-copy declaration is invalid.

`SIFR-PYZC-0001` belongs to the **Embedded Python zero-copy** diagnostic family. It means: an advanced-data ownership, buffer layout, or hidden-copy declaration is invalid.

## Why It Happens

A Python zero-copy buffer, Arrow, DLPack, or array-interface exchange failed lifetime or layout checks.

<Info>
  Use `sifr --explain SIFR-PYZC-0001` 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-PYZC-0001`                                                                                                        |
| Family                 | `PYZC`                                                                                                                  |
| Severity               | Error                                                                                                                   |
| Stability              | stable                                                                                                                  |
| Owner                  | `sifr_lowering`                                                                                                         |
| Representative fixture | `crates/sifr_lowering/src/lower/python_buffer_contract_tests.rs::buffer_policy_and_return_contract_fail_with_pyzc_0001` |

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