Struct OutputFailure 

pub struct OutputFailure<S> {
    pub error: RunError,
    pub report: Option<RunReport<S>>,
}

A typed turn that produced no value — and everything it reported anyway.

The turn still happened. It spent tokens, it may have been ended by a bound rather than by the work, and it wrote a whole stream into the sink the caller lent it. A typed turn used to build that RunReport and then drop it on the floor, returning a bare RunError; a caller charging runs against a shared allowance, or deciding between re-asking with a clearer schema and backing off, was left to reconstruct from the event log what the run had already written down. Library first (ADR-0003) is judged by the in-process Rust consumer, and this is the shape that consumer needs: the error and the account.

The error is deliberately the same RunError the turn returned before, not a second vocabulary for the same failure — two names for one thing is how a host ends up matching on the wrong one. From hands it straight back, so a caller that wants nothing but the error writes .await.map_err(RunError::from)? and receives exactly what it always did: RunError::OutputMismatch for an answer T refused, RunError::Runtime for a turn that failed or never called the terminal tool.

Distinct from RunFailure, which is mentra’s own error as retained inside a report.

Fields

error: RunError

Why there is no value, in the same terms as before this type existed.

On a runtime failure this is where mentra’s original error lives, rather than in RunReport::failure: a RuntimeError is not Clone and cannot be in two places, and the error is where a caller reaching for ? looks. The validated path (output_parts_validated_with_options) returns Ok, so there the report is the only home and keeps it (ADR-0024 §4).

report: Option<RunReport<S>>

Everything the turn reported before it came up empty, sink included.

None only when there was no turn to report on — an empty prompt, an option set that cannot be drawn, a sink that refused a write, a forwarding task that did not come back. Every failure of the turn itself carries its report.

Trait Implementations

impl<S: Debug> Debug for OutputFailure<S>

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

Formats the value using the given formatter.

impl<S> Display for OutputFailure<S>

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

Formats the value using the given formatter.

impl<S: Debug> Error for OutputFailure<S>

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl<S> From<OutputFailure<S>> for RunError

fn from(failure: OutputFailure<S>) -> Self

The error alone, worded exactly as the typed turn worded it before it carried a report. The report — and with it the sink — is dropped here, which is the whole cost of ? and the reason the richer type is what the turn returns.

impl<S> From<RunError> for OutputFailure<S>

fn from(error: RunError) -> Self

A failure with no turn behind it. See report.