Hmbown/CodeWhale · error · anyhow::Error

invalid duration component: {num_buf:?}

Error message

invalid duration component: {num_buf:?}

What it means

parse_duration_secs walks the string as runs of digits terminated by unit letters d/h/m/s. When a unit letter arrives but the digit buffer is empty (or the accumulated number fails i64 parsing, i.e. overflow), this error names the offending buffer. Notably there is no millisecond unit: "100ms" fails here because the trailing s follows an empty buffer.

Source

Thrown at crates/cli/src/metrics.rs:80

pub fn parse_since(s: &str) -> Result<DateTime<Utc>> {
    let s = s.trim().to_ascii_lowercase();
    let s = s.strip_prefix("now-").unwrap_or(&s);
    let secs = parse_duration_secs(s)?;
    Ok(Utc::now() - Duration::seconds(secs))
}

fn parse_duration_secs(s: &str) -> Result<i64> {
    // Walk through the string accumulating numbers and consuming unit suffixes.
    let mut total: i64 = 0;
    let mut num_buf = String::new();

    for ch in s.chars() {
        match ch {
            '0'..='9' => num_buf.push(ch),
            'd' | 'h' | 'm' | 's' => {
                let n: i64 = num_buf
                    .parse()
                    .map_err(|_| anyhow::anyhow!("invalid duration component: {num_buf:?}"))?;
                num_buf.clear();
                let factor = match ch {
                    'd' => 86_400,
                    'h' => 3_600,
                    'm' => 60,
                    's' => 1,
                    _ => unreachable!(),
                };
                total += n * factor;
            }
            _ => anyhow::bail!("unrecognised character {ch:?} in duration {s:?}"),
        }
    }

    if !num_buf.is_empty() {
        // Trailing bare number — treat as seconds.
        let n: i64 = num_buf.parse()?;
        total += n;

View on GitHub (pinned to 8880682c63)

Solutions

1. Express the duration with supported units only: d/h/m/s (e.g. "100ms" -> "0s" is invalid, use "1s" or drop it)
2. Ensure every unit letter is preceded by digits — no stray or doubled units
3. Keep each component under i64 range; split into multiple components instead
4. Use the accepted "now-2h" prefix form where the flag documents it

Example fix

# before
 codewhale metrics --since 100ms   # error: invalid duration component: ""

# after
 codewhale metrics --since 1s

fn valid_duration(s: &str) -> bool {
    let s = s.trim().to_ascii_lowercase();
    let s = s.strip_prefix("now-").unwrap_or(&s);
    !s.is_empty() && s.chars().all(|c| c.is_ascii_digit() || matches!(c, 'd' | 'h' | 'm' | 's')) && !s.ends_with(|c: char| matches!(c, 'd' | 'h' | 'm' | 's')) == false
}

When it happens

Trigger: Passing "100ms" or "1500ms" to a --since-style flag; a bare unit like "d" or "h" with no number; a huge component like "99999999999999999999s" overflowing i64.

Common situations: Assuming humantime/ms support; copy-pasting latency-style durations into a retention window flag; scripting with empty variables producing a lone unit.

Related errors

• unrecognised character {ch:?} in duration {s:?}
• duration {s:?} resolved to zero seconds
• invalid JSON payload at key {MCP_SERVER_DEFINITIONS_KEY}; co
• could not parse match block after {signature!r}
• No local {} API key was found in config, the secret store, o

AI-assisted analysis of Hmbown/CodeWhale@8880682c63 (2026-08-16). Data as JSON: /api/errors/23a5bf9a3882af6c. Report an issue: GitHub.