sigoden/aichat · error · anyhow::Error

Invalid chunk_overlay

Error message

Invalid chunk_overlay

What it means

Error surfaced by the RAG setup prompt set_chunk_overlay when the entered text cannot be parsed as usize. The interactive validator normally rejects non-integers ('Must be a integer'), so this bail is the fallback for unparseable chunk overlay input during create_config.

Solutions

1. Enter a plain non-negative integer, e.g. 100
2. Re-run setup and correct the value at the prompt
3. Set the overlay value directly in the RAG config file

Example fix

// at the prompt
// before: chunk overlay: 10%
// after:  chunk overlay: 10

fn valid_chunk_overlay(s: &str) -> bool { s.trim().parse::<usize>().is_ok() }

let ov: usize = prompt_and_parse("chunk overlay").map_err(|_| {
    eprintln!("Chunk overlay must be a plain integer"); retry()
})?;

When it happens

Trigger: Entering non-numeric or otherwise unparsable text at the 'Set chunk overlay:' prompt during rag create_config.

Common situations: Typing a float or units ('0.2', '10%'); empty input slipping through; locale-formatted digits.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Invalid chunk_size
• Unknown RAG
• No RAG
• No models
• Unknown client

AI-assisted analysis of sigoden/aichat@82976d349a (2026-09-09). Data as JSON: /api/errors/1245375c1a2ddab0. Report an issue: GitHub.

Appendix: source

Thrown at src/rag/mod.rs:917

    if let Some(help_message) = &help_message {
        text = text.with_help_message(help_message);
    }
    let value = text.prompt()?;
    value.parse().map_err(|_| anyhow!("Invalid chunk_size"))
}

fn set_chunk_overlay(default_value: usize) -> Result<usize> {
    let value = Text::new("Set chunk overlay:")
        .with_default(&default_value.to_string())
        .with_validator(move |text: &str| {
            let out = match text.parse::<usize>() {
                Ok(_) => Validation::Valid,
                Err(_) => Validation::Invalid("Must be a integer".into()),
            };
            Ok(out)
        })
        .prompt()?;
    value.parse().map_err(|_| anyhow!("Invalid chunk_overlay"))
}

fn add_documents() -> Result<Vec<String>> {
    let text = Text::new("Add documents:")
        .with_validator(required!("This field is required"))
        .with_help_message("e.g. file;dir/;dir/**/*.{md,mdx};loader:resource;url;website/**")
        .prompt()?;
    let paths = text
        .split(';')
        .filter_map(|v| {
            let v = v.trim().to_string();
            if v.is_empty() {
                None
            } else {
                Some(v)
            }
        })
        .collect();

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