janhq/jan · error · RagError

IoError

IoError

Error message

IO error: {0}

What it means

RagError::IoError wraps a std::io::Error as a string when filesystem operations fail during RAG ingestion or retrieval (displayed as "IO error: {0}"). Via the provided From impl, any std::io::Error from reading files or accessing paths is converted automatically. It indicates OS-level IO trouble, not document parsing or format issues.

Solutions

1. Read the wrapped message to identify the exact OS error (NotFound vs PermissionDenied).
2. Verify the file path exists and is readable before ingestion (fs::metadata check).
3. Ensure the plugin's index/storage directories exist and are writable.
4. Handle transient failures (network drives) with a retry around ingestion.

Example fix

// before
let text = read_document(path)?;

// after
let text = read_document(path).map_err(|e| match e {
    RagError::IoError(msg) => {
        eprintln!("cannot read {path:?}: {msg}");
        e
    }
    other => other,
})?;

// Rust: verify the file is readable before RAG operations
fn readable(path: &Path) -> bool {
    std::fs::File::open(path).is_ok()
}

fn as_io_error(err: &RagError) -> Option<&str> {
    match err { RagError::IoError(m) => Some(m), _ => None }
}

match rag.ingest(path) {
    Err(RagError::IoError(msg)) => {
        log::warn!("io problem with {path:?}: {msg}");
        retry_with_backoff(|| rag.ingest(path));
    }
    other => other?,
}

When it happens

Trigger: Ingesting a file that doesn't exist, lacks read permission, or was deleted mid-operation; failing to create/write index or cache directories used by the RAG plugin.

Common situations: Moved or renamed files between selection and ingestion; permission-restricted folders; missing index directory on first run; network mounts dropped mid-read.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• IO error
• Failed to parse document
• IO error
• IO error
• ParseError

AI-assisted analysis of janhq/jan@7205d770c1 (2026-09-17). Data as JSON: /api/errors/3fa3be1116f803ea. Report an issue: GitHub.

Appendix: source

Thrown at src-tauri/plugins/tauri-plugin-rag/src/error.rs:11

use serde::{Deserialize, Serialize};

#[derive(Debug, thiserror::Error, Serialize, Deserialize)]
pub enum RagError {
    #[error("Failed to parse document: {0}")]
    ParseError(String),

    #[error("Unsupported file type: {0}")]
    UnsupportedFileType(String),

    #[error("IO error: {0}")]
    IoError(String),
}

impl From<std::io::Error> for RagError {
    fn from(err: std::io::Error) -> Self {
        RagError::IoError(err.to_string())
    }
}

View on GitHub (pinned to 7205d770c1)