affaan-m/ECC · error · anyhow::Error

minimum mean delta must be finite

Error message

minimum mean delta must be finite

What it means

PromotionPolicy::validate rejects a min_mean_delta that is NaN or infinite. The threshold must be a finite number so the mean-delta comparison in compare() is deterministic; it fires on a corrupt or nonsensical policy value.

Source

Thrown at ecc2/src/harness_eval.rs:511

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Comparison {
    pub passed: bool,
    pub sample_count: usize,
    pub candidate_mean: f64,
    pub baseline_mean: f64,
    pub mean_delta: f64,
    pub win_rate: f64,
    pub failures: Vec<String>,
}

impl PromotionPolicy {
    pub fn validate(self) -> Result<()> {
        if self.min_samples == 0 {
            bail!("minimum samples must be positive");
        }
        if !self.min_mean_delta.is_finite() {
            bail!("minimum mean delta must be finite");
        }
        if !self.min_win_rate.is_finite() || !(0.0..=1.0).contains(&self.min_win_rate) {
            bail!("minimum win rate must be between 0 and 1");
        }
        Ok(())
    }

    pub fn compare(self, samples: &[PairedSample]) -> Result<Comparison> {
        self.validate()?;
        if samples.is_empty() {
            bail!("samples cannot be empty");
        }
        if samples
            .iter()
            .map(|sample| sample.seed)
            .collect::<BTreeSet<_>>()
            .len()
            != samples.len()

View on GitHub (pinned to 06c5e118c4)

Solutions

1. Provide a finite number for minimum mean delta; NaN and Infinity are rejected.
2. Check the computation producing the delta for division by zero or overflow.

When it happens

Trigger: Thrown at ecc2/src/harness_eval.rs:511 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of affaan-m/ECC@06c5e118c4 (2026-08-18). Data as JSON: /api/errors/18211a4979d06eb4. Report an issue: GitHub.