Hmbown/CodeWhale · error · anyhow::Error

Unsupported RRULE field '{key}' for CRON. Allowed: FREQ,EXPR

Error message

Unsupported RRULE field '{key}' for CRON. Allowed: FREQ,EXPR

What it means

parse_cron_schedule rejects any RRULE key other than FREQ and EXPR for FREQ=CRON. Keys are uppercased before the check, so it is case-insensitive; a missing or empty EXPR produces 'CRON schedules require EXPR' instead.

Source

Thrown at crates/tui/src/automation_manager.rs:615

}

fn parse_once_schedule(parts: &BTreeMap<String, String>) -> Result<AutomationSchedule> {
    for key in parts.keys() {
        if key != "FREQ" && key != "AT" {
            bail!("Unsupported RRULE field '{key}' for ONCE. Allowed: FREQ,AT");
        }
    }
    let raw_at = parts
        .get("AT")
        .ok_or_else(|| anyhow::anyhow!("ONCE schedules require AT"))?;
    let at = parse_once_at(raw_at)?;
    Ok(AutomationSchedule::Once { at })
}

fn parse_cron_schedule(parts: &BTreeMap<String, String>) -> Result<AutomationSchedule> {
    for key in parts.keys() {
        if key != "FREQ" && key != "EXPR" {
            bail!("Unsupported RRULE field '{key}' for CRON. Allowed: FREQ,EXPR");
        }
    }
    let expr = parts
        .get("EXPR")
        .map(|value| value.trim().to_string())
        .filter(|value| !value.is_empty())
        .ok_or_else(|| anyhow::anyhow!("CRON schedules require EXPR"))?;
    ParsedCronExpr::parse(&expr)?;
    Ok(AutomationSchedule::Cron { expr })
}

fn parse_once_at(raw: &str) -> Result<DateTime<Utc>> {
    let trimmed = raw.trim();
    if let Ok(at) = DateTime::parse_from_rfc3339(trimmed) {
        return Ok(at.with_timezone(&Utc));
    }
    for format in ["%Y-%m-%dT%H:%M:%S", "%Y-%m-%dT%H:%M"] {
        if let Ok(naive) = NaiveDateTime::parse_from_str(trimmed, format) {

View on GitHub (pinned to 0c42157ee5)

Solutions

Keep only FREQ and EXPR: FREQ=CRON;EXPR=*/17 * * * *
Encode cadence entirely inside the 5-field EXPR
Move one-shot times to FREQ=ONCE;AT=...
Dry-run parse_rrule before persisting

Example fix

// before
rrule = "FREQ=CRON;EXPR=*/17 * * * *;INTERVAL=2"

// after
rrule = "FREQ=CRON;EXPR=*/17 * * * *"

Defensive patterns

Strategy: validation

Validate before calling

fn valid_cron_rrule(rrule: &str) -> bool {
    rrule.split(';')
        .filter_map(|s| s.split_once('=').map(|(k, _)| k.trim().to_ascii_uppercase()))
        .all(|k| k == "FREQ" || k == "EXPR")
}

Prevention

Encode all cadence inside the 5-field EXPR
Strip RRULE-style extras when converting HOURLY/WEEKLY rules to CRON
Validate the assembled FREQ=CRON;EXPR=... string with parse_rrule
Keep one-shot times in FREQ=ONCE;AT=... instead of EXPR

When it happens

Trigger: AutomationSchedule::parse_rrule("FREQ=CRON;EXPR=*/17 * * * *;INTERVAL=2"), or any FREQ=CRON rule carrying BYDAY, BYHOUR, AT, or similar extra keys.

Common situations: Mixing RRULE-style fields into cron rules; converting an HOURLY rule to CRON and forgetting to remove INTERVAL/BYDAY.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/fa3bd608ba343a4d. Report an issue: GitHub.