> ## 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-PYENV-0005: Selected Python interpreter is not supported CPython.

> Selected Python interpreter is not supported CPython.

`SIFR-PYENV-0005` belongs to the **Embedded CPython environment** diagnostic family. It means: selected Python interpreter is not supported CPython.

## Why It Happens

The selected Python environment is missing, malformed, ambiguous, or fails probe/ABI checks. Configure exactly one root-application uv environment and ensure the interpreter, site-packages, and declared imports are available.

<Info>
  Use `sifr --explain SIFR-PYENV-0005` 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-PYENV-0005`                                                                                          |
| Family                 | `PYENV`                                                                                                    |
| Severity               | Error                                                                                                      |
| Stability              | stable                                                                                                     |
| Owner                  | `sifr_package::python`                                                                                     |
| Representative fixture | `crates/sifr_package/src/python/probe_validation_tests.rs::probe_rejects_non_cpython_json_with_pyenv_0005` |

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