What causes "Could not create a ChunkedUnevenCore" in bevyengine/bevy?

Match on the variant to learn the failed invariant: ZeroWidth, NotEnoughSamples, MismatchedLengths, or NonDivisibleLengths.

bevyengine/bevy · error · ChunkedUnevenCoreError

Could not create a ChunkedUnevenCore

Error message

Could not create a ChunkedUnevenCore

What it means

ChunkedUnevenCoreError is the umbrella error for ChunkedUnevenCore::new and ChunkedUnevenCore::new_width_inferred. The enum carries four concrete variants (ZeroWidth, NotEnoughSamples, MismatchedLengths, NonDivisibleLengths); this top-level text appears when the error is displayed without matching a variant, hiding which check failed. ChunkedUnevenCore stores vector-valued samples ('width' values per time) interpolated at uneven times.

Source

Thrown at crates/bevy_math/src/curve/cores.rs:485

#[cfg_attr(feature = "bevy_reflect", derive(Reflect))]
pub struct ChunkedUnevenCore<T> {
    /// The times, one for each sample.
    ///
    /// # Invariants
    /// This must always have a length of at least 2, be sorted, and have no duplicated or
    /// non-finite times.
    pub times: Vec<f32>,

    /// The values that are used in sampling. Each width-worth of these correspond to a single sample.
    ///
    /// # Invariants
    /// The length of this vector must always be some fixed integer multiple of that of `times`.
    pub values: Vec<T>,
}

/// An error that indicates that a [`ChunkedUnevenCore`] could not be formed.
#[derive(Debug, Error)]
#[error("Could not create a ChunkedUnevenCore")]
pub enum ChunkedUnevenCoreError {
    /// The width of a `ChunkedUnevenCore` cannot be zero.
    #[error("Chunk width must be at least 1")]
    ZeroWidth,

    /// At least two sample times are necessary to interpolate in `ChunkedUnevenCore`.
    #[error(
        "Need at least two unique samples to create a ChunkedUnevenCore, but {samples} were provided"
    )]
    NotEnoughSamples {
        /// The number of samples that were provided.
        samples: usize,
    },

    /// The length of the value buffer is supposed to be the `width` times the number of samples.
    #[error("Expected {expected} total values based on width, but {actual} were provided")]
    MismatchedLengths {
        /// The expected length of the value buffer.

View on GitHub (pinned to 396ca72708)

Solutions

Match on the variant to learn the failed invariant: ZeroWidth, NotEnoughSamples, MismatchedLengths, or NonDivisibleLengths.
Log with {:?} to keep the variant payload.
Prefer new() over new_width_inferred — it validates more and gives the clearer MismatchedLengths error.

Example fix

// before
let core = ChunkedUnevenCore::new(times, values, width).map_err(|e| log::error!("core failed: {e}"))?; // generic

// after
let core = match ChunkedUnevenCore::new(times, values, width) {
    Ok(core) => core,
    Err(e @ (ChunkedUnevenCoreError::ZeroWidth
    | ChunkedUnevenCoreError::NotEnoughSamples { .. }
    | ChunkedUnevenCoreError::MismatchedLengths { .. }
    | ChunkedUnevenCoreError::NonDivisibleLengths { .. })) => {
        log::error!("chunked core rejected: {e:?}");
        return;
    }
};

Defensive patterns

Strategy: try-catch

Try / catch

match ChunkedUnevenCore::new(times, values, width) {
    Ok(core) => core,
    Err(e) => {
        error!("chunked core rejected: {e:?}"); // variant + payload stay visible
        return Ok(());
    }
}

Prevention

Always format ChunkedUnevenCoreError with {:?} or match variants; never plain {e}.
Prefer new(width explicit) over new_width_inferred for better error specificity.
Route all chunked-core construction through one helper with variant-level logging.

When it happens

Trigger: Any failing ChunkedUnevenCore::new(times, values, width) or new_width_inferred(times, values) call whose error is then formatted with {} (e.g. through anyhow) so only the umbrella message is printed.

Common situations: Building curves whose samples are vectors/matrices (e.g. multi-channel animation data) and logging failures generically in a plugin or asset loader.

Related errors

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/f721a6d27495756a. Report an issue: GitHub.