huggingface/candle · error

No data in file {}

Error message

No data in file {}

What it means

Raised by `read_imatrix` (imatrix_file::read) in candle-core/src/quantized/imatrix_file.rs when the i32 entry count read from the start of an importance-matrix (imatrix) file is less than 1. It means the imatrix file is empty or corrupt and contains no calibration entries.

Source

Thrown at candle-core/src/quantized/imatrix_file.rs:37

    })?;
    let mut buffer = Vec::new();
    file.read_to_end(&mut buffer).map_err(|e| {
        crate::Error::msg(format!(
            "Failed to read file {}: {}",
            fname.as_ref().display(),
            e
        ))
    })?;

    let mut cursor = Cursor::new(buffer);

    let n_entries = cursor
        .read_i32::<LittleEndian>()
        .map_err(|e| crate::Error::msg(format!("Failed to read number of entries: {e}")))?
        as usize;

    if n_entries < 1 {
        crate::bail!("No data in file {}", fname.as_ref().display());
    }

    for i in 0..n_entries {
        // Read length of the name
        let len = cursor.read_i32::<LittleEndian>().map_err(|e| {
            crate::Error::msg(format!(
                "Failed to read name length for entry {}: {}",
                i + 1,
                e
            ))
        })? as usize;

        // Read the name
        let mut name_buf = vec![0u8; len];
        cursor.read_exact(&mut name_buf).map_err(|e| {
            crate::Error::msg(format!("Failed to read name for entry {}: {}", i + 1, e))
        })?;
        let name = String::from_utf8(name_buf).map_err(|e| {

View on GitHub (pinned to d5fee525bf)

Solutions

1. Regenerate the imatrix file with the quantization toolchain and confirm it is non-empty
2. Check file size > 4 bytes before loading and verify the path is correct
3. Re-download the imatrix file if it came from a remote source

Example fix

// before
let imatrix = load_imatrix("imatrix.gguf")?; // empty file
// after
let meta = std::fs::metadata("imatrix.gguf")?;
assert!(meta.len() > 4, "imatrix file is empty or truncated");
let imatrix = load_imatrix("imatrix.gguf")?;

let meta = std::fs::metadata("imatrix.dat")?;
if meta.len() <= 4 {
    return Err(anyhow!("imatrix file is empty or truncated ({} bytes)", meta.len()));
}

match load_imatrix(&fname) {
    Ok(m) => m,
    Err(e) if e.to_string().contains("No data in file") => {
        eprintln!("imatrix file has zero entries; regenerate it");
        return Err(e.into());
    }
    Err(e) => return Err(e.into()),
}

When it happens

Trigger: load_imatrix on a zero-byte or truncated file whose first i32 reads as 0 or negative (e.g. all-zero bytes from a failed download).

Common situations: Pointing at an empty placeholder file; interrupted imatrix generation producing an empty output; wrong path passed for the imatrix argument.

Related errors

• Invalid nval for entry {}: {}
• {} is a dummy type and does not support parsing
• unrecognized value-type {v:#08x}

AI-assisted analysis of huggingface/candle@d5fee525bf (2026-09-02). Data as JSON: /api/errors/a8b9067bc6e7342e. Report an issue: GitHub.