Import failing with Segment fault 11

[Sirorezka]

Read full issue history here: qdrant/fastembed#630

My specs:

Apple M4 Pro
macOs "26.4.1 (25E253)"
Python 3.14.3
conda 26.3.2
rustc 1.93.1 (01f6ddf75 2026-02-11)
maturin 1.11.5
cargo 1.93.1

The error that I get:

from py_rust_stemmers import SnowballStemmer
print("running steamer...")
SnowballStemmer("english")
print("done")

I get the following output:

running steamer...
Segmentation fault: 11

[Sirorezka]

The solution that worked for me was to update code dependency "pyo3" to "v0.28.3" and rewrite the src/lib.rs code.

Here is version that worked for me:

use pyo3::prelude::*;
use rayon::prelude::*;
// Import the stemmer implementation from the rust-stemmers library
extern crate rust_stemmers;
use rust_stemmers::{Algorithm, Stemmer};

// Create a Python class to expose the stemmer functionality
#[pyclass]
pub struct SnowballStemmer {
    stemmer: Stemmer,
}

#[pymethods]
impl SnowballStemmer {
    #[new]
    fn new(lang: String) -> PyResult<Self> {  // Changed: &str -> String, added PyResult
        let algorithm = match lang.to_lowercase().as_str() {
            "arabic" => Algorithm::Arabic,
            "danish" => Algorithm::Danish,
            "dutch" => Algorithm::Dutch,
            "english" => Algorithm::English,
            "finnish" => Algorithm::Finnish,
            "french" => Algorithm::French,
            "german" => Algorithm::German,
            "greek" => Algorithm::Greek,
            "hungarian" => Algorithm::Hungarian,
            "italian" => Algorithm::Italian,
            "norwegian" => Algorithm::Norwegian,
            "portuguese" => Algorithm::Portuguese,
            "romanian" => Algorithm::Romanian,
            "russian" => Algorithm::Russian,
            "spanish" => Algorithm::Spanish,
            "swedish" => Algorithm::Swedish,
            "tamil" => Algorithm::Tamil,
            "turkish" => Algorithm::Turkish,
            _ => return Err(pyo3::exceptions::PyValueError::new_err(
                format!("Unsupported language: {}", lang)
            )),  // Changed: panic -> PyErr
        };
        let stemmer = Stemmer::create(algorithm);
        Ok(SnowballStemmer { stemmer })  // Wrapped in Ok
    }

    #[inline(always)]
    fn stem_word(&self, input: String) -> String {  // Changed: &str -> String
        self.stemmer.stem(&input).into_owned()  // Added & to convert String to &str
    }

    #[inline(always)]
    pub fn stem_words_parallel(&self, inputs: Vec<String>) -> Vec<String> {  // Changed: Vec<&str> -> Vec<String>
        inputs
            .into_par_iter()
            .map(|word| self.stemmer.stem(&word).into_owned())  // Added & to convert String to &str
            .collect()
    }

    #[inline(always)]
    pub fn stem_words(&self, inputs: Vec<String>) -> Vec<String> {
        inputs
            .into_iter()
            .map(|word| self.stemmer.stem(&word).into_owned())
            .collect()
    }
}

/// This module is required for the Python interpreter to access the Rust functions.
#[pymodule]
fn py_rust_stemmers(_py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> {  // Changed: &PyModule -> &Bound<'_, PyModule>
    m.add_class::<SnowballStemmer>()?;
    Ok(())
}