Enum QueryError 

pub enum QueryError {
    Suspend,
    Cycle {
        path: Vec<String>,
    },
    Cancelled,
    MissingDependency {
        description: String,
    },
    UserError(Arc<Error>),
}

Query errors including both system-level and user errors.

User errors can be propagated using the ? operator, which automatically converts any Into<anyhow::Error> type into QueryError::UserError.

Variants

Suspend

Query is waiting for async loading to complete.

This is returned when a dependency is still loading via a background task. Use runtime.query_async() to wait for loading to complete, or handle explicitly in your query logic.

Cycle

Dependency cycle detected.

The query graph contains a cycle, which would cause infinite recursion. The path contains a debug representation of the cycle.

Fields

path: Vec<String>

Debug representation of the queries forming the cycle.

Cancelled

Query execution was cancelled.

MissingDependency

A required dependency is missing.

Fields

description: String

Description of the missing dependency.

UserError(Arc<Error>)

User-defined error.

This variant allows user errors to be propagated through the query system using the ? operator. Any type implementing Into<anyhow::Error> can be converted to this variant.

Unlike system errors (Suspend, Cycle, etc.), UserError results are cached and participate in early cutoff optimization.

Trait Implementations

impl Clone for QueryError

fn clone(&self) -> QueryError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QueryError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for QueryError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Into<Error>> From<T> for QueryError

fn from(err: T) -> Self

Converts to this type from the input type.