herdrdev/herdr · warning · io::Error

{flag} must be greater than 0

Error message

{flag} must be greater than 0

What it means

parse_terminal_dimension parses a u16 successfully but then rejects the value 0 (src/cli.rs:671), because a zero-sized terminal is meaningless. It returns io::ErrorKind::InvalidInput with '{flag} must be greater than 0'. Note that a literal "0" parses fine as u16, so only this second check catches it.

Source

Thrown at src/cli.rs:671

    }

    Ok(Ok(TerminalSessionOptions {
        target: target.clone(),
        cols,
        rows,
        takeover,
    }))
}

fn parse_terminal_dimension(raw: &str, flag: &str) -> std::io::Result<u16> {
    let parsed = raw.parse::<u16>().map_err(|_| {
        std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("{flag} must be an integer between 1 and {}", u16::MAX),
        )
    })?;
    if parsed == 0 {
        return Err(std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("{flag} must be greater than 0"),
        ));
    }
    Ok(parsed)
}

fn terminal_title(args: &[String]) -> std::io::Result<i32> {
    match args.first().map(|arg| arg.as_str()) {
        Some("set") => {
            if args.len() != 2 {
                eprintln!("usage: herdr terminal title set <title>");
                return Ok(2);
            }
            print_response(&send_request(&Request {
                id: "cli:terminal:title:set".into(),
                method: Method::ClientWindowTitleSet(ClientWindowTitleSetParams {
                    title: args[1].clone(),

View on GitHub (pinned to f457cff4f2)

Solutions

1. Pass a positive integer (>= 1) for every dimension flag
2. Default unset shell variables explicitly: --rows "${ROWS:-24}"
3. Debug wrapper scripts that compute dimensions from tput/terminal size queries

Example fix

# before
herdr session new --rows 0 --cols 80

# after
herdr session new --rows 1 --cols 80

let rows: u16 = args.rows.parse().unwrap_or(24);
if rows == 0 { return Err("rows must be >= 1".into()); }

When it happens

Trigger: Passing exactly 0 to a terminal dimension flag (e.g. --rows 0 or --cols 0) on a command parsed by parse_terminal_session_options. Values like "-1" or "abc" fail earlier with the range message from error 11.

Common situations: Unset numeric env vars defaulting to 0, arithmetic in scripts producing 0 (e.g. $(tput lines) failing), or attempting to create a hidden/minimal pane.

Related errors

• {flag} must be an integer between 1 and {}
• expected sha256 must be 64 hexadecimal characters
• {REMOTE_BINARY_ENV_VAR} path is not a file: {}
• api request line is too large
• timed out reading api request

AI-assisted analysis of herdrdev/herdr@f457cff4f2 (2026-08-28). Data as JSON: /api/errors/eec0c1b47a49edbb. Report an issue: GitHub.